diff --git a/.gitignore b/.gitignore
index 2f89f8a..ea6562f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -14,5 +14,4 @@ srfi-*.sld
 srfi.*.scm
 srfi.*.sld
 reports
-r7rs-tests.scm
 snow.*
diff --git a/r7rs-tests.scm b/r7rs-tests.scm
new file mode 100644
index 0000000..6596074
--- /dev/null
+++ b/r7rs-tests.scm
@@ -0,0 +1,2516 @@
+;; -*- coding: utf-8 -*-
+
+(import (scheme base) (scheme char) (scheme lazy)
+        (scheme inexact) (scheme complex) (scheme time)
+        (scheme file) (scheme read) (scheme write)
+        (scheme eval) (scheme process-context) (scheme case-lambda)
+        (scheme r5rs)
+        (chibi test)  ; or (srfi 64)
+        )
+
+;; R7RS test suite.  Covers all procedures and syntax in the small
+;; language except `delete-file'.  Currently assumes full-unicode
+;; support, the full numeric tower and all standard libraries
+;; provided.
+;;
+;; Uses the (chibi test) library which is written in portable R7RS.
+;; This is mostly a subset of SRFI-64, providing test-begin, test-end
+;; and test, which could be defined as something like:
+;;
+;;   (define (test-begin . o) #f)
+;;
+;;   (define (test-end . o) #f)
+;;
+;;   (define-syntax test
+;;     (syntax-rules ()
+;;       ((test expected expr)
+;;        (let ((res expr))
+;;          (cond
+;;           ((not (equal? expr expected))
+;;            (display "FAIL: ")
+;;            (write 'expr)
+;;            (display ": expected ")
+;;            (write expected)
+;;            (display " but got ")
+;;            (write res)
+;;            (newline)))))))
+;;
+;; however (chibi test) provides nicer output, timings, and
+;; approximate equivalence for floating point numbers.
+
+(test-begin "R7RS")
+
+(test-begin "4.1 Primitive expression types")
+
+(let ()
+  (define x 28)
+  (test 28 x))
+
+(test 'a (quote a))
+(test #(a b c) (quote #(a b c)))
+(test '(+ 1 2) (quote (+ 1 2)))
+
+(test 'a 'a)
+(test #(a b c) '#(a b c))
+(test '() '())
+(test '(+ 1 2) '(+ 1 2))
+(test '(quote a) '(quote a))
+(test '(quote a) ''a)
+
+(test "abc" '"abc")
+(test "abc" "abc")
+(test 145932 '145932)
+(test 145932 145932)
+(test #t '#t)
+(test #t #t)
+
+(test 7 (+ 3 4))
+(test 12 ((if #f + *) 3 4))
+
+(test 8 ((lambda (x) (+ x x)) 4))
+(define reverse-subtract
+  (lambda (x y) (- y x)))
+(test 3 (reverse-subtract 7 10))
+(define add4
+  (let ((x 4))
+    (lambda (y) (+ x y))))
+(test 10 (add4 6))
+
+(test '(3 4 5 6) ((lambda x x) 3 4 5 6))
+(test '(5 6) ((lambda (x y . z) z)
+ 3 4 5 6))
+
+(test 'yes (if (> 3 2) 'yes 'no))
+(test 'no (if (> 2 3) 'yes 'no))
+(test 1 (if (> 3 2)
+    (- 3 2)
+    (+ 3 2)))
+(let ()
+  (define x 2)
+  (test 3 (+ x 1)))
+
+(test-end)
+
+(test-begin "4.2 Derived expression types")
+
+(test 'greater
+    (cond ((> 3 2) 'greater)
+          ((< 3 2) 'less)))
+
+(test 'equal
+    (cond ((> 3 3) 'greater)
+          ((< 3 3) 'less)
+          (else 'equal)))
+
+(test 2
+    (cond ((assv 'b '((a 1) (b 2))) => cadr)
+          (else #f)))
+
+(test 'composite
+    (case (* 2 3)
+      ((2 3 5 7) 'prime)
+      ((1 4 6 8 9) 'composite)))
+
+(test 'c
+    (case (car '(c d))
+      ((a e i o u) 'vowel)
+      ((w y) 'semivowel)
+      (else => (lambda (x) x))))
+
+(test '((other . z) (semivowel . y) (other . x)
+        (semivowel . w) (vowel . u))
+    (map (lambda (x)
+           (case x
+             ((a e i o u) => (lambda (w) (cons 'vowel w)))
+             ((w y) (cons 'semivowel x))
+             (else => (lambda (w) (cons 'other w)))))
+         '(z y x w u)))
+
+(test #t (and (= 2 2) (> 2 1)))
+(test #f (and (= 2 2) (< 2 1)))
+(test '(f g) (and 1 2 'c '(f g)))
+(test #t (and))
+
+(test #t (or (= 2 2) (> 2 1)))
+(test #t (or (= 2 2) (< 2 1)))
+(test #f (or #f #f #f))
+(test '(b c) (or (memq 'b '(a b c))
+    (/ 3 0)))
+
+(test 6 (let ((x 2) (y 3))
+  (* x y)))
+
+(test 35 (let ((x 2) (y 3))
+  (let ((x 7)
+        (z (+ x y)))
+    (* z x))))
+
+(test 70 (let ((x 2) (y 3))
+  (let* ((x 7)
+         (z (+ x y)))
+    (* z x))))
+
+(test #t
+    (letrec ((even?
+              (lambda (n)
+                (if (zero? n)
+                    #t
+                    (odd? (- n 1)))))
+             (odd?
+              (lambda (n)
+                (if (zero? n)
+                    #f
+                    (even? (- n 1))))))
+      (even? 88)))
+
+(test 5
+    (letrec* ((p
+               (lambda (x)
+                 (+ 1 (q (- x 1)))))
+              (q
+               (lambda (y)
+                 (if (zero? y)
+                     0
+                     (+ 1 (p (- y 1))))))
+              (x (p 5))
+              (y x))
+             y))
+
+;; By Jussi Piitulainen <jpiitula@ling.helsinki.fi>
+;; and John Cowan <cowan@mercury.ccil.org>:
+;; http://lists.scheme-reports.org/pipermail/scheme-reports/2013-December/003876.html
+(define (means ton)
+  (letrec*
+     ((mean
+        (lambda (f g)
+          (f (/ (sum g ton) n))))
+      (sum
+        (lambda (g ton)
+          (if (null? ton)
+            (+)
+            (if (number? ton)
+                (g ton)
+                (+ (sum g (car ton))
+                   (sum g (cdr ton)))))))
+      (n (sum (lambda (x) 1) ton)))
+    (values (mean values values)
+            (mean exp log)
+            (mean / /))))
+(let*-values (((a b c) (means '(8 5 99 1 22))))
+  (test 27 a)
+  (test 9.728 b)
+  (test 1800/497 c))
+
+(let*-values (((root rem) (exact-integer-sqrt 32)))
+  (test 35 (* root rem)))
+
+(test '(1073741824 0)
+    (let*-values (((root rem) (exact-integer-sqrt (expt 2 60))))
+      (list root rem)))
+
+(test '(1518500249 3000631951)
+    (let*-values (((root rem) (exact-integer-sqrt (expt 2 61))))
+      (list root rem)))
+
+(test '(815238614083298888 443242361398135744)
+    (let*-values (((root rem) (exact-integer-sqrt (expt 2 119))))
+      (list root rem)))
+
+(test '(1152921504606846976 0)
+    (let*-values (((root rem) (exact-integer-sqrt (expt 2 120))))
+      (list root rem)))
+
+(test '(1630477228166597776 1772969445592542976)
+    (let*-values (((root rem) (exact-integer-sqrt (expt 2 121))))
+      (list root rem)))
+
+(test '(31622776601683793319 62545769258890964239)
+    (let*-values (((root rem) (exact-integer-sqrt (expt 10 39))))
+      (list root rem)))
+
+(let*-values (((root rem) (exact-integer-sqrt (expt 2 140))))
+  (test 0 rem)
+  (test (expt 2 140) (square root)))
+
+(test '(x y x y) (let ((a 'a) (b 'b) (x 'x) (y 'y))
+  (let*-values (((a b) (values x y))
+                ((x y) (values a b)))
+    (list a b x y))))
+
+(test 'ok (let-values () 'ok))
+
+(test 1 (let ((x 1))
+	  (let*-values ()
+	    (define x 2)
+	    #f)
+	  x))
+
+(let ()
+  (define x 0)
+  (set! x 5)
+  (test 6 (+ x 1)))
+
+(test #(0 1 2 3 4) (do ((vec (make-vector 5))
+     (i 0 (+ i 1)))
+    ((= i 5) vec)
+  (vector-set! vec i i)))
+
+(test 25 (let ((x '(1 3 5 7 9)))
+  (do ((x x (cdr x))
+       (sum 0 (+ sum (car x))))
+      ((null? x) sum))))
+
+(test '((6 1 3) (-5 -2))
+    (let loop ((numbers '(3 -2 1 6 -5))
+               (nonneg '())
+               (neg '()))
+      (cond ((null? numbers) (list nonneg neg))
+            ((>= (car numbers) 0)
+             (loop (cdr numbers)
+                   (cons (car numbers) nonneg)
+                   neg))
+            ((< (car numbers) 0)
+             (loop (cdr numbers)
+                   nonneg
+                   (cons (car numbers) neg))))))
+
+(test 3 (force (delay (+ 1 2))))
+
+(test '(3 3)  
+    (let ((p (delay (+ 1 2))))
+      (list (force p) (force p))))
+
+(define integers
+  (letrec ((next
+            (lambda (n)
+              (delay (cons n (next (+ n 1)))))))
+    (next 0)))
+(define head
+  (lambda (stream) (car (force stream))))
+(define tail
+  (lambda (stream) (cdr (force stream))))
+
+(test 2 (head (tail (tail integers))))
+
+(define (stream-filter p? s)
+  (delay-force
+   (if (null? (force s)) 
+       (delay '())
+       (let ((h (car (force s)))
+             (t (cdr (force s))))
+         (if (p? h)
+             (delay (cons h (stream-filter p? t)))
+             (stream-filter p? t))))))
+
+(test 5 (head (tail (tail (stream-filter odd? integers)))))
+
+(let ()
+  (define x 5)
+  (define count 0)
+  (define p
+    (delay (begin (set! count (+ count 1))
+                  (if (> count x)
+                      count
+                      (force p)))))
+  (test 6 (force p))
+  (test 6 (begin (set! x 10) (force p))))
+
+(test #t (promise? (delay (+ 2 2))))
+(test #t (promise? (make-promise (+ 2 2))))
+(test #t
+    (let ((x (delay (+ 2 2))))
+      (force x)
+      (promise? x)))
+(test #t
+    (let ((x (make-promise (+ 2 2))))
+      (force x)
+      (promise? x)))
+(test 4 (force (make-promise (+ 2 2))))
+(test 4 (force (make-promise (make-promise (+ 2 2)))))
+
+(define radix
+  (make-parameter
+   10
+   (lambda (x)
+     (if (and (integer? x) (<= 2 x 16))
+         x
+         (error "invalid radix")))))
+(define (f n) (number->string n (radix)))
+(test "12" (f 12))
+(test "1100" (parameterize ((radix 2))
+  (f 12)))
+(test "12" (f 12))
+
+(test '(list 3 4) `(list ,(+ 1 2) 4))
+(let ((name 'a)) (test '(list a (quote a)) `(list ,name ',name)))
+(test '(a 3 4 5 6 b) `(a ,(+ 1 2) ,@(map abs '(4 -5 6)) b))
+(test #(10 5 4 16 9 8)
+    `#(10 5 ,(square 2) ,@(map square '(4 3)) 8))
+(test '(a `(b ,(+ 1 2) ,(foo 4 d) e) f)
+    `(a `(b ,(+ 1 2) ,(foo ,(+ 1 3) d) e) f) )
+(let ((name1 'x)
+      (name2 'y))
+   (test '(a `(b ,x ,'y d) e) `(a `(b ,,name1 ,',name2 d) e)))
+(test '(list 3 4) (quasiquote (list (unquote (+ 1 2)) 4)) )
+(test `(list ,(+ 1 2) 4) (quasiquote (list (unquote (+ 1 2)) 4)))
+
+(define any-arity
+  (case-lambda 
+    (() 'zero)
+    ((x) x)
+    ((x y) (cons x y))
+    ((x y z) (list x y z))
+    (args (cons 'many args))))
+
+(test 'zero (any-arity))
+(test 1 (any-arity 1))
+(test '(1 . 2) (any-arity 1 2))
+(test '(1 2 3) (any-arity 1 2 3))
+(test '(many 1 2 3 4) (any-arity 1 2 3 4))
+
+(define rest-arity
+  (case-lambda 
+    (() '(zero))
+    ((x) (list 'one x))
+    ((x y) (list 'two x y))
+    ((x y . z) (list 'more x y z))))
+
+(test '(zero) (rest-arity))
+(test '(one 1) (rest-arity 1))
+(test '(two 1 2) (rest-arity 1 2))
+(test '(more 1 2 (3)) (rest-arity 1 2 3))
+
+(define dead-clause
+  (case-lambda
+    ((x . y) 'many)
+    (() 'none)
+    (foo 'unreachable)))
+
+(test 'none (dead-clause))
+(test 'many (dead-clause 1))
+(test 'many (dead-clause 1 2))
+(test 'many (dead-clause 1 2 3))
+
+(test-end)
+
+(test-begin "4.3 Macros")
+
+(test 'now (let-syntax
+               ((when (syntax-rules ()
+                        ((when test stmt1 stmt2 ...)
+                         (if test
+                             (begin stmt1
+                                    stmt2 ...))))))
+             (let ((if #t))
+               (when if (set! if 'now))
+               if)))
+
+(test 'outer (let ((x 'outer))
+  (let-syntax ((m (syntax-rules () ((m) x))))
+    (let ((x 'inner))
+      (m)))))
+
+(test 7 (letrec-syntax
+  ((my-or (syntax-rules ()
+            ((my-or) #f)
+            ((my-or e) e)
+            ((my-or e1 e2 ...)
+             (let ((temp e1))
+               (if temp
+                   temp
+                   (my-or e2 ...)))))))
+  (let ((x #f)
+        (y 7)
+        (temp 8)
+        (let odd?)
+        (if even?))
+    (my-or x
+           (let temp)
+           (if y)
+           y))))
+
+(define-syntax be-like-begin1
+  (syntax-rules ()
+    ((be-like-begin1 name)
+     (define-syntax name
+       (syntax-rules ()
+         ((name expr (... ...))
+          (begin expr (... ...))))))))
+(be-like-begin1 sequence1)
+(test 3 (sequence1 0 1 2 3))
+
+(define-syntax be-like-begin2
+  (syntax-rules ()
+    ((be-like-begin2 name)
+     (define-syntax name
+       (... (syntax-rules ()
+              ((name expr ...)
+               (begin expr ...))))))))
+(be-like-begin2 sequence2)
+(test 4 (sequence2 1 2 3 4))
+
+(define-syntax be-like-begin3
+  (syntax-rules ()
+    ((be-like-begin3 name)
+     (define-syntax name
+       (syntax-rules dots ()
+         ((name expr dots)
+          (begin expr dots)))))))
+(be-like-begin3 sequence3)
+(test 5 (sequence3 2 3 4 5))
+
+;; ellipsis escape
+(define-syntax elli-esc-1
+  (syntax-rules ()
+    ((_)
+     '(... ...))
+    ((_ x)
+     '(... (x ...)))
+    ((_ x y)
+     '(... (... x y)))))
+
+(test '... (elli-esc-1))
+(test '(100 ...) (elli-esc-1 100))
+(test '(... 100 200) (elli-esc-1 100 200))
+
+;; Syntax pattern with ellipsis in middle of proper list.
+(define-syntax part-2
+  (syntax-rules ()
+    ((_ a b (m n) ... x y)
+     (vector (list a b) (list m ...) (list n ...) (list x y)))
+    ((_ . rest) 'error)))
+(test '#((10 43) (31 41 51) (32 42 52) (63 77))
+    (part-2 10 (+ 21 22) (31 32) (41 42) (51 52) (+ 61 2) 77))
+;; Syntax pattern with ellipsis in middle of improper list.
+(define-syntax part-2x
+  (syntax-rules ()
+    ((_ (a b (m n) ... x y . rest))
+     (vector (list a b) (list m ...) (list n ...) (list x y)
+             (cons "rest:" 'rest)))
+    ((_ . rest) 'error)))
+(test '#((10 43) (31 41 51) (32 42 52) (63 77) ("rest:"))
+    (part-2x (10 (+ 21 22) (31 32) (41 42) (51 52) (+ 61 2) 77)))
+(test '#((10 43) (31 41 51) (32 42 52) (63 77) ("rest:" . "tail"))
+    (part-2x (10 (+ 21 22) (31 32) (41 42) (51 52) (+ 61 2) 77 . "tail")))
+
+;; underscore
+(define-syntax underscore
+  (syntax-rules ()
+    ((foo _) '_)))
+(test '_ (underscore foo))
+
+(let ()
+  (define-syntax underscore2
+    (syntax-rules ()
+      ((underscore2 (a _) ...) 42)))
+  (test 42 (underscore2 (1 2))))
+
+(define-syntax count-to-2
+  (syntax-rules ()
+    ((_) 0)
+    ((_ _) 1)
+    ((_ _ _) 2)
+    ((_ . _) 'many)))
+(test '(2 0 many)
+    (list (count-to-2 a b) (count-to-2) (count-to-2 a b c d)))
+
+(define-syntax count-to-2_
+  (syntax-rules (_)
+    ((_) 0)
+    ((_ _) 1)
+    ((_ _ _) 2)
+    ((x . y) 'fail)))
+(test '(2 0 fail fail)
+    (list (count-to-2_ _ _) (count-to-2_)
+          (count-to-2_ a b) (count-to-2_ a b c d)))
+
+(define-syntax jabberwocky
+  (syntax-rules ()
+    ((_ hatter)
+     (begin
+       (define march-hare 42)
+       (define-syntax hatter
+         (syntax-rules ()
+           ((_) march-hare)))))))
+(jabberwocky mad-hatter)
+(test 42 (mad-hatter))
+
+(test 'ok (let ((=> #f)) (cond (#t => 'ok))))
+
+(let ()
+  (define x 1)
+  (let-syntax ()
+    (define x 2)
+    #f)
+  (test 1 x))
+
+(let ()
+ (define-syntax foo
+   (syntax-rules ()
+     ((foo bar y)
+      (define-syntax bar
+        (syntax-rules ()
+          ((bar x) 'y))))))
+ (foo bar x)
+ (test 'x (bar 1)))
+
+(begin
+  (define-syntax ffoo
+    (syntax-rules ()
+      ((ffoo ff)
+       (begin
+         (define (ff x)
+           (gg x))
+         (define (gg x)
+           (* x x))))))
+  (ffoo ff)
+  (test 100 (ff 10)))
+
+(let-syntax ((vector-lit
+               (syntax-rules ()
+                 ((vector-lit)
+                  '#(b)))))
+  (test '#(b) (vector-lit)))
+
+(let ()
+  ;; forward hygienic refs
+  (define-syntax foo399
+    (syntax-rules () ((foo399) (bar399))))
+  (define (quux399)
+    (foo399))
+  (define (bar399)
+    42)
+  (test 42 (quux399)))
+
+(let-syntax
+    ((m (syntax-rules ()
+          ((m x) (let-syntax
+                     ((n (syntax-rules (k)
+                           ((n x) 'bound-identifier=?)
+                           ((n y) 'free-identifier=?))))
+                   (n z))))))
+  (test 'bound-identifier=? (m k)))
+
+;; literal has priority to ellipsis (R7RS 4.3.2)
+(let ()
+  (define-syntax elli-lit-1
+    (syntax-rules ... (...)
+      ((_ x)
+       '(x ...))))
+  (test '(100 ...) (elli-lit-1 100)))
+
+;; bad ellipsis
+#|
+(test 'error
+      (guard (exn (else 'error))
+        (eval
+         '(define-syntax bad-elli-1
+            (syntax-rules ()
+              ((_ ... x)
+               '(... x))))
+         (interaction-environment))))
+
+(test 'error
+      (guard (exn (else 'error))
+        (eval
+         '(define-syntax bad-elli-2
+            (syntax-rules ()
+              ((_ (... x))
+               '(... x))))
+         (interaction-environment))))
+|#
+
+(test-end)
+
+(test-begin "5 Program structure")
+
+(define add3
+  (lambda (x) (+ x 3)))
+(test 6 (add3 3))
+(define first car)
+(test 1 (first '(1 2)))
+
+(test 45 (let ((x 5))
+  (define foo (lambda (y) (bar x y)))
+  (define bar (lambda (a b) (+ (* a b) a)))
+  (foo (+ x 3))))
+
+(test 'ok
+    (let ()
+      (define-values () (values))
+      'ok))
+(test 1
+    (let ()
+      (define-values (x) (values 1))
+      x))
+(test 3
+    (let ()
+      (define-values x (values 1 2))
+      (apply + x)))
+(test 3
+    (let ()
+      (define-values (x y) (values 1 2))
+      (+ x y)))
+(test 6
+    (let ()
+      (define-values (x y z) (values 1 2 3))
+      (+ x y z)))
+(test 10
+    (let ()
+      (define-values (x y . z) (values 1 2 3 4))
+      (+ x y (car z) (cadr z))))
+
+(test '(2 1) (let ((x 1) (y 2))
+  (define-syntax swap!
+    (syntax-rules ()
+      ((swap! a b)
+       (let ((tmp a))
+         (set! a b)
+         (set! b tmp)))))
+  (swap! x y)
+  (list x y)))
+
+;; Records
+
+(define-record-type <pare>
+  (kons x y)
+  pare?
+  (x kar set-kar!)
+  (y kdr))
+
+(test #t (pare? (kons 1 2)))
+(test #f (pare? (cons 1 2)))
+(test 1 (kar (kons 1 2)))
+(test 2 (kdr (kons 1 2)))
+(test 3 (let ((k (kons 1 2)))
+          (set-kar! k 3)
+          (kar k)))
+
+(test-end)
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; 6 Standard Procedures
+
+(test-begin "6.1 Equivalence Predicates")
+
+(test #t (eqv? 'a 'a))
+(test #f (eqv? 'a 'b))
+(test #t (eqv? 2 2))
+(test #t (eqv? '() '()))
+(test #t (eqv? 100000000 100000000))
+(test #f (eqv? (cons 1 2) (cons 1 2)))
+(test #f (eqv? (lambda () 1)
+               (lambda () 2)))
+(test #f (eqv? #f 'nil))
+
+(define gen-counter
+  (lambda ()
+    (let ((n 0))
+      (lambda () (set! n (+ n 1)) n))))
+(test #t
+    (let ((g (gen-counter)))
+      (eqv? g g)))
+(test #f (eqv? (gen-counter) (gen-counter)))
+(define gen-loser
+  (lambda ()
+    (let ((n 0))
+      (lambda () (set! n (+ n 1)) 27))))
+(test #t (let ((g (gen-loser)))
+  (eqv? g g)))
+
+(test #f
+(letrec ((f (lambda () (if (eqv? f g) 'f 'both)))
+         (g (lambda () (if (eqv? f g) 'g 'both))))
+   (eqv? f g)))
+
+(test #t
+    (let ((x '(a)))
+      (eqv? x x)))
+
+(test #t (eq? 'a 'a))
+(test #f (eq? (list 'a) (list 'a)))
+(test #t (eq? '() '()))
+(test #t
+    (let ((x '(a)))
+      (eq? x x)))
+(test #t
+    (let ((x '#()))
+      (eq? x x)))
+(test #t
+    (let ((p (lambda (x) x)))
+      (eq? p p)))
+
+(test #t (equal? 'a 'a))
+(test #t (equal? '(a) '(a)))
+(test #t (equal? '(a (b) c)
+                 '(a (b) c)))
+(test #t (equal? "abc" "abc"))
+(test #t (equal? 2 2))
+(test #t (equal? (make-vector 5 'a)
+                 (make-vector 5 'a)))
+
+(test-end)
+
+(test-begin "6.2 Numbers")
+
+(test #t (complex? 3+4i))
+(test #t (complex? 3))
+(test #t (real? 3))
+(test #t (real? -2.5+0i))
+(test #f (real? -2.5+0.0i))
+(test #t (real? #e1e10))
+(test #t (real? +inf.0))
+(test #f (rational? -inf.0))
+(test #f (rational? +nan.0))
+(test #t (rational? 9007199254740991.0))
+(test #t (rational? 9007199254740992.0))
+(test #t (rational? 1.7976931348623157e308))
+(test #t (rational? 6/10))
+(test #t (rational? 6/3))
+(test #t (integer? 3+0i))
+(test #t (integer? 3.0))
+(test #t (integer? 8/4))
+
+(test #f (exact? 3.0))
+(test #t (exact? #e3.0))
+(test #t (inexact? 3.))
+
+(test #t (exact-integer? 32))
+(test #f (exact-integer? 32.0))
+(test #f (exact-integer? 32/5))
+
+(test #t (finite? 3))
+(test #f (finite? +inf.0))
+(test #f (finite? 3.0+inf.0i))
+
+(test #f (infinite? 3))
+(test #t (infinite? +inf.0))
+(test #f (infinite? +nan.0))
+(test #t (infinite? 3.0+inf.0i))
+
+(test #t (nan? +nan.0))
+(test #f (nan? 32))
+;; (test #t (nan? +nan.0+5.0i))
+(test #f (nan? 1+2i))
+
+(test #t (= 1 1.0 1.0+0.0i))
+(test #f (= 1.0 1.0+1.0i))
+(test #t (< 1 2 3))
+(test #f (< 1 1 2))
+(test #t (> 3.0 2.0 1.0))
+(test #f (> -3.0 2.0 1.0))
+(test #t (<= 1 1 2))
+(test #f (<= 1 2 1))
+(test #t (>= 2 1 1))
+(test #f (>= 1 2 1))
+(test #f (< +nan.0 0))
+(test #f (> +nan.0 0))
+(test #f (< +nan.0 0.0))
+(test #f (> +nan.0 0.0))
+(test '(#t #f) (list (<= 1 1 2) (<= 2 1 3)))
+(test #f (= 9007199254740992.0 9007199254740993))
+
+;; From R7RS 6.2.6 Numerical operations:
+;;
+;; These predicates are required to be transitive.
+;;
+;; _Note:_ The traditional implementations of these predicates in
+;; Lisp-like languages, which involve converting all arguments to inexact
+;; numbers if any argument is inexact, are not transitive.
+
+;; Example from Alan Bawden
+(let ((a (- (expt 2 1000) 1))
+      (b (inexact (expt 2 1000))) ; assuming > single-float-epsilon
+      (c (+ (expt 2 1000) 1)))
+  (test #t (if (and (= a b) (= b c))
+               (= a c)
+               #t)))
+
+;; From CLtL 12.3. Comparisons on Numbers:
+;;
+;;  Let _a_ be the result of (/ 10.0 single-float-epsilon), and let
+;;  _j_ be the result of (floor a). ..., all of (<= a j), (< j (+ j
+;;  1)), and (<= (+ j 1) a) would be true; transitivity would then
+;;  imply that (< a a) ought to be true ...
+
+;; Transliteration from Jussi Piitulainen
+(define single-float-epsilon
+  (do ((eps 1.0 (* eps 2.0)))
+      ((= eps (+ eps 1.0)) eps)))
+
+(let* ((a (/ 10.0 single-float-epsilon))
+       (j (exact a)))
+  (test #t (if (and (<= a j) (< j (+ j 1)))
+               (not (<= (+ j 1) a))
+               #t)))
+
+(test #t (zero? 0))
+(test #t (zero? 0.0))
+(test #t (zero? 0.0+0.0i))
+(test #f (zero? 1))
+(test #f (zero? -1))
+
+(test #f (positive? 0))
+(test #f (positive? 0.0))
+(test #t (positive? 1))
+(test #t (positive? 1.0))
+(test #f (positive? -1))
+(test #f (positive? -1.0))
+(test #t (positive? +inf.0))
+(test #f (positive? -inf.0))
+(test #f (positive? +nan.0))
+
+(test #f (negative? 0))
+(test #f (negative? 0.0))
+(test #f (negative? 1))
+(test #f (negative? 1.0))
+(test #t (negative? -1))
+(test #t (negative? -1.0))
+(test #f (negative? +inf.0))
+(test #t (negative? -inf.0))
+(test #f (negative? +nan.0))
+
+(test #f (odd? 0))
+(test #t (odd? 1))
+(test #t (odd? -1))
+(test #f (odd? 102))
+
+(test #t (even? 0))
+(test #f (even? 1))
+(test #t (even? -2))
+(test #t (even? 102))
+
+(test 3 (max 3))
+(test 4 (max 3 4))
+(test 4.0 (max 3.9 4))
+(test 5.0 (max 5 3.9 4))
+(test +inf.0 (max 100 +inf.0))
+(test 3 (min 3))
+(test 3 (min 3 4))
+(test 3.0 (min 3 3.1))
+(test -inf.0 (min -inf.0 -100))
+
+(test 7 (+ 3 4))
+(test 3 (+ 3))
+(test 0 (+))
+(test 4 (* 4))
+(test 1 (*))
+
+(test -1 (- 3 4))
+(test -6 (- 3 4 5))
+(test -3 (- 3))
+(test -3/2 (- 3/2))
+(test -3/2-i (- 3/2+i))
+(test 3/20 (/ 3 4 5))
+(test 1/3 (/ 3))
+
+(test 1073741824 (/ -1073741824 -1))
+(test 1073741824 (quotient -1073741824 -1))
+(test 0 (remainder -1073741824 -1))
+(test 4611686018427387904 (/ -4611686018427387904 -1))
+(test 4611686018427387904 (quotient -4611686018427387904 -1))
+(test 0 (remainder -4611686018427387904 -1))
+
+(test 7 (abs -7))
+(test 7 (abs 7))
+
+(test-values (values 2 1) (floor/ 5 2))
+(test-values (values -3 1) (floor/ -5 2))
+(test-values (values -3 -1) (floor/ 5 -2))
+(test-values (values 2 -1) (floor/ -5 -2))
+(test-values (values 2 1) (truncate/ 5 2))
+(test-values (values -2 -1) (truncate/ -5 2))
+(test-values (values -2 1) (truncate/ 5 -2))
+(test-values (values 2 -1) (truncate/ -5 -2))
+(test-values (values 2.0 -1.0) (truncate/ -5.0 -2))
+
+(test 1 (modulo 13 4))
+(test 1 (remainder 13 4))
+
+(test 3 (modulo -13 4))
+(test -1 (remainder -13 4))
+
+(test -3 (modulo 13 -4))
+(test 1 (remainder 13 -4))
+
+(test -1 (modulo -13 -4))
+(test -1 (remainder -13 -4))
+
+(test -1.0 (remainder -13 -4.0))
+
+(test 4 (gcd 32 -36))
+(test 0 (gcd))
+(test 288 (lcm 32 -36))
+(test 288.0 (lcm 32.0 -36))
+(test 1 (lcm))
+
+(test 3 (numerator (/ 6 4)))
+(test 2 (denominator (/ 6 4)))
+(test 2.0 (denominator (inexact (/ 6 4))))
+(test 11.0 (numerator 5.5))
+(test 2.0 (denominator 5.5))
+(test 5.0 (numerator 5.0))
+(test 1.0 (denominator 5.0))
+
+(test -5.0 (floor -4.3))
+(test -4.0 (ceiling -4.3))
+(test -4.0 (truncate -4.3))
+(test -4.0 (round -4.3))
+
+(test 3.0 (floor 3.5))
+(test 4.0 (ceiling 3.5))
+(test 3.0 (truncate 3.5))
+(test 4.0 (round 3.5))
+
+(test 4 (round 7/2))
+(test 7 (round 7))
+(test 1 (round 7/10))
+(test -4 (round -7/2))
+(test -7 (round -7))
+(test -1 (round -7/10))
+
+(test 1/3 (rationalize (exact .3) 1/10))
+(test #i1/3 (rationalize .3 1/10))
+
+(test 1.0 (inexact (exp 0))) ;; may return exact number
+(test 20.0855369231877 (exp 3))
+
+(test 0.0 (inexact (log 1))) ;; may return exact number
+(test 1.0 (log (exp 1)))
+(test 42.0 (log (exp 42)))
+(test 2.0 (log 100 10))
+(test 12.0 (log 4096 2))
+
+(test 0.0 (inexact (sin 0))) ;; may return exact number
+(test 1.0 (sin 1.5707963267949))
+(test 1.0 (inexact (cos 0))) ;; may return exact number
+(test -1.0 (cos 3.14159265358979))
+(test 0.0 (inexact (tan 0))) ;; may return exact number
+(test 1.5574077246549 (tan 1))
+
+(test 0.0 (inexact (asin 0))) ;; may return exact number
+(test 1.5707963267949 (asin 1))
+(test 0.0 (inexact (acos 1))) ;; may return exact number
+(test 3.14159265358979 (acos -1))
+
+;; (test 0.0-0.0i (asin 0+0.0i))
+;; (test 1.5707963267948966+0.0i (acos 0+0.0i))
+
+(test 0.0 (atan 0.0 1.0))
+(test -0.0 (atan -0.0 1.0))
+(test 0.785398163397448 (atan 1.0 1.0))
+(test 1.5707963267949 (atan 1.0 0.0))
+(test 2.35619449019234 (atan 1.0 -1.0))
+(test 3.14159265358979 (atan 0.0 -1.0))
+(test -3.14159265358979 (atan -0.0 -1.0)) ;
+(test -2.35619449019234 (atan -1.0 -1.0))
+(test -1.5707963267949 (atan -1.0 0.0))
+(test -0.785398163397448 (atan -1.0 1.0))
+;; (test undefined (atan 0.0 0.0))
+
+(test 1764 (square 42))
+(test 4 (square 2))
+
+(test 3.0 (inexact (sqrt 9)))
+(test 1.4142135623731 (sqrt 2))
+(test 0.0+1.0i (inexact (sqrt -1)))
+(test 0.0+1.0i (sqrt -1.0-0.0i))
+
+(test '(2 0) (call-with-values (lambda () (exact-integer-sqrt 4)) list))
+(test '(2 1) (call-with-values (lambda () (exact-integer-sqrt 5)) list))
+
+(test 27 (expt 3 3))
+(test 1 (expt 0 0))
+(test 0 (expt 0 1))
+(test 1.0 (expt 0.0 0))
+(test 0.0 (expt 0 1.0))
+
+(test 1+2i (make-rectangular 1 2))
+
+(test 0.54030230586814+0.841470984807897i (make-polar 1 1))
+
+(test 1 (real-part 1+2i))
+
+(test 2 (imag-part 1+2i))
+
+(test 2.23606797749979 (magnitude 1+2i))
+
+(test 1.10714871779409 (angle 1+2i))
+
+(test 1.0 (inexact 1))
+(test #t (inexact? (inexact 1)))
+(test 1 (exact 1.0))
+(test #t (exact? (exact 1.0)))
+
+(test 100 (string->number "100"))
+(test 256 (string->number "100" 16))
+(test 100.0 (string->number "1e2"))
+(test #f (string->number "1 2"))
+
+(test-end)
+
+(test-begin "6.3 Booleans")
+
+(test #t #t)
+(test #f #f)
+(test #f '#f)
+
+(test #f (not #t))
+(test #f (not 3))
+(test #f (not (list 3)))
+(test #t (not #f))
+(test #f (not '()))
+(test #f (not (list)))
+(test #f (not 'nil))
+
+(test #t (boolean? #f))
+(test #f (boolean? 0))
+(test #f (boolean? '()))
+
+(test #t (boolean=? #t #t))
+(test #t (boolean=? #f #f))
+(test #f (boolean=? #t #f))
+(test #t (boolean=? #f #f #f))
+(test #f (boolean=? #t #t #f))
+
+(test-end)
+
+(test-begin "6.4 Lists")
+
+(let* ((x (list 'a 'b 'c))
+       (y x))
+  (test '(a b c) (values y))
+  (test #t (list? y))
+  (set-cdr! x 4)
+  (test '(a . 4) (values x))
+  (test #t (eqv? x y))
+  (test #f (list? y))
+  (set-cdr! x x)
+  (test #f (list? x)))
+
+(test #t (pair? '(a . b)))
+(test #t (pair? '(a b c)))
+(test #f (pair? '()))
+(test #f (pair? '#(a b)))
+
+(test '(a) (cons 'a '()))
+(test '((a) b c d) (cons '(a) '(b c d)))
+(test '("a" b c) (cons "a" '(b c)))
+(test '(a . 3) (cons 'a 3))
+(test '((a b) . c) (cons '(a b) 'c))
+
+(test 'a (car '(a b c)))
+(test '(a) (car '((a) b c d)))
+(test 1 (car '(1 . 2)))
+
+(test '(b c d) (cdr '((a) b c d)))
+(test 2 (cdr '(1 . 2)))
+(define (g) '(constant-list))
+
+(test #t (list? '(a b c)))
+(test #t (list? '()))
+(test #f (list? '(a . b)))
+(test #f (let ((x (list 'a))) (set-cdr! x x) (list? x)))
+
+(test '(3 3) (make-list 2 3))
+
+(test '(a 7 c) (list 'a (+ 3 4) 'c))
+(test '() (list))
+
+(test 3 (length '(a b c)))
+(test 3 (length '(a (b) (c d e))))
+(test 0 (length '()))
+
+(test '(x y) (append '(x) '(y)))
+(test '(a b c d) (append '(a) '(b c d)))
+(test '(a (b) (c)) (append '(a (b)) '((c))))
+
+(test '(a b c . d) (append '(a b) '(c . d)))
+(test 'a (append '() 'a))
+
+(test '(c b a) (reverse '(a b c)))
+(test '((e (f)) d (b c) a) (reverse '(a (b c) d (e (f)))))
+
+(test '(d e) (list-tail '(a b c d e) 3))
+
+(test 'c (list-ref '(a b c d) 2))
+(test 'c (list-ref '(a b c d)
+          (exact (round 1.8))))
+
+(test '(0 ("Sue" "Sue") "Anna")
+    (let ((lst (list 0 '(2 2 2 2) "Anna")))
+      (list-set! lst 1 '("Sue" "Sue"))
+      lst))
+
+(test '(a b c) (memq 'a '(a b c)))
+(test '(b c) (memq 'b '(a b c)))
+(test #f (memq 'a '(b c d)))
+(test #f (memq (list 'a) '(b (a) c)))
+(test '((a) c) (member (list 'a) '(b (a) c)))
+(test '("b" "c") (member "B" '("a" "b" "c") string-ci=?))
+(test '(101 102) (memv 101 '(100 101 102)))
+
+(let ()
+  (define e '((a 1) (b 2) (c 3)))
+  (test '(a 1) (assq 'a e))
+  (test '(b 2) (assq 'b e))
+  (test #f (assq 'd e)))
+
+(test #f (assq (list 'a) '(((a)) ((b)) ((c)))))
+(test '((a)) (assoc (list 'a) '(((a)) ((b)) ((c)))))
+(test '(2 4) (assoc 2.0 '((1 1) (2 4) (3 9)) =))
+(test '(5 7) (assv 5 '((2 3) (5 7) (11 13))))
+
+(test '(1 2 3) (list-copy '(1 2 3)))
+(test "foo" (list-copy "foo"))
+(test '() (list-copy '()))
+(test '(3 . 4) (list-copy '(3 . 4)))
+(test '(6 7 8 . 9) (list-copy '(6 7 8 . 9)))
+(let* ((l1 '((a b) (c d) e))
+       (l2 (list-copy l1)))
+  (test l2 '((a b) (c d) e))
+  (test #t (eq? (car l1) (car l2)))
+  (test #t (eq? (cadr l1) (cadr l2)))
+  (test #f (eq? (cdr l1) (cdr l2)))
+  (test #f (eq? (cddr l1) (cddr l2))))
+
+(test-end)
+
+(test-begin "6.5 Symbols")
+
+(test #t (symbol? 'foo))
+(test #t (symbol? (car '(a b))))
+(test #f (symbol? "bar"))
+(test #t (symbol? 'nil))
+(test #f (symbol? '()))
+(test #f (symbol? #f))
+
+(test #t (symbol=? 'a 'a))
+(test #f (symbol=? 'a 'A))
+(test #t (symbol=? 'a 'a 'a))
+(test #f (symbol=? 'a 'a 'A))
+
+(test "flying-fish"     
+(symbol->string 'flying-fish))
+(test "Martin" (symbol->string 'Martin))
+(test "Malvina" (symbol->string (string->symbol "Malvina")))
+
+(test 'mISSISSIppi (string->symbol "mISSISSIppi"))
+(test #t (eq? 'bitBlt (string->symbol "bitBlt")))
+(test #t (eq? 'LollyPop (string->symbol (symbol->string 'LollyPop))))
+(test #t (string=? "K. Harper, M.D."
+                   (symbol->string (string->symbol "K. Harper, M.D."))))
+
+(test-end)
+
+(test-begin "6.6 Characters")
+
+(test #t (char? #\a))
+(test #f (char? "a"))
+(test #f (char? 'a))
+(test #f (char? 0))
+
+(test #t (char=? #\a #\a #\a))
+(test #f (char=? #\a #\A))
+(test #t (char<? #\a #\b #\c))
+(test #f (char<? #\a #\a))
+(test #f (char<? #\b #\a))
+(test #f (char>? #\a #\b))
+(test #f (char>? #\a #\a))
+(test #t (char>? #\c #\b #\a))
+(test #t (char<=? #\a #\b #\b))
+(test #t (char<=? #\a #\a))
+(test #f (char<=? #\b #\a))
+(test #f (char>=? #\a #\b))
+(test #t (char>=? #\a #\a))
+(test #t (char>=? #\b #\b #\a))
+
+(test #t (char-ci=? #\a #\a))
+(test #t (char-ci=? #\a #\A #\a))
+(test #f (char-ci=? #\a #\b))
+(test #t (char-ci<? #\a #\B #\c))
+(test #f (char-ci<? #\A #\a))
+(test #f (char-ci<? #\b #\A))
+(test #f (char-ci>? #\A #\b))
+(test #f (char-ci>? #\a #\A))
+(test #t (char-ci>? #\c #\B #\a))
+(test #t (char-ci<=? #\a #\B #\b))
+(test #t (char-ci<=? #\A #\a))
+(test #f (char-ci<=? #\b #\A))
+(test #f (char-ci>=? #\A #\b))
+(test #t (char-ci>=? #\a #\A))
+(test #t (char-ci>=? #\b #\B #\a))
+
+(test #t (char-alphabetic? #\a))
+(test #f (char-alphabetic? #\space))
+(test #t (char-numeric? #\0))
+(test #f (char-numeric? #\.))
+(test #f (char-numeric? #\a))
+(test #t (char-whitespace? #\space))
+(test #t (char-whitespace? #\tab))
+(test #t (char-whitespace? #\newline))
+(test #f (char-whitespace? #\_))
+(test #f (char-whitespace? #\a))
+(test #t (char-upper-case? #\A))
+(test #f (char-upper-case? #\a))
+(test #f (char-upper-case? #\3))
+(test #t (char-lower-case? #\a))
+(test #f (char-lower-case? #\A))
+(test #f (char-lower-case? #\3))
+
+(test #t (char-alphabetic? #\Λ))
+(test #f (char-alphabetic? #\x0E50))
+(test #t (char-upper-case? #\Λ))
+(test #f (char-upper-case? #\λ))
+(test #f (char-lower-case? #\Λ))
+(test #t (char-lower-case? #\λ))
+(test #f (char-numeric? #\Λ))
+(test #t (char-numeric? #\x0E50))
+(test #t (char-whitespace? #\x1680))
+
+(test 0 (digit-value #\0))
+(test 3 (digit-value #\3))
+(test 9 (digit-value #\9))
+(test 4 (digit-value #\x0664))
+(test 0 (digit-value #\x0AE6))
+(test #f (digit-value #\.))
+(test #f (digit-value #\-))
+
+(test 97 (char->integer #\a))
+(test #\a (integer->char 97))
+
+(test #\A (char-upcase #\a))
+(test #\A (char-upcase #\A))
+(test #\a (char-downcase #\a))
+(test #\a (char-downcase #\A))
+(test #\a (char-foldcase #\a))
+(test #\a (char-foldcase #\A))
+
+(test #\Λ (char-upcase #\λ))
+(test #\Λ (char-upcase #\Λ))
+(test #\λ (char-downcase #\λ))
+(test #\λ (char-downcase #\Λ))
+(test #\λ (char-foldcase #\λ))
+(test #\λ (char-foldcase #\Λ))
+
+(test-end)
+
+(test-begin "6.7 Strings")
+
+(test #t (string? ""))
+(test #t (string? " "))
+(test #f (string? 'a))
+(test #f (string? #\a))
+
+(test 3 (string-length (make-string 3)))
+(test "---" (make-string 3 #\-))
+
+(test "" (string))
+(test "---" (string #\- #\- #\-))
+(test "kitten" (string #\k #\i #\t #\t #\e #\n))
+
+(test 0 (string-length ""))
+(test 1 (string-length "a"))
+(test 3 (string-length "abc"))
+
+(test #\a (string-ref "abc" 0))
+(test #\b (string-ref "abc" 1))
+(test #\c (string-ref "abc" 2))
+
+(test "a-c" (let ((str (string #\a #\b #\c))) (string-set! str 1 #\-) str))
+
+(test (string #\a #\x1F700 #\c)
+    (let ((s (string #\a #\b #\c)))
+      (string-set! s 1 #\x1F700)
+      s))
+
+(test #t (string=? "" ""))
+(test #t (string=? "abc" "abc" "abc"))
+(test #f (string=? "" "abc"))
+(test #f (string=? "abc" "aBc"))
+
+(test #f (string<? "" ""))
+(test #f (string<? "abc" "abc"))
+(test #t (string<? "abc" "abcd" "acd"))
+(test #f (string<? "abcd" "abc"))
+(test #t (string<? "abc" "bbc"))
+
+(test #f (string>? "" ""))
+(test #f (string>? "abc" "abc"))
+(test #f (string>? "abc" "abcd"))
+(test #t (string>? "acd" "abcd" "abc"))
+(test #f (string>? "abc" "bbc"))
+
+(test #t (string<=? "" ""))
+(test #t (string<=? "abc" "abc"))
+(test #t (string<=? "abc" "abcd" "abcd"))
+(test #f (string<=? "abcd" "abc"))
+(test #t (string<=? "abc" "bbc"))
+
+(test #t (string>=? "" ""))
+(test #t (string>=? "abc" "abc"))
+(test #f (string>=? "abc" "abcd"))
+(test #t (string>=? "abcd" "abcd" "abc"))
+(test #f (string>=? "abc" "bbc"))
+
+(test #t (string-ci=? "" ""))
+(test #t (string-ci=? "abc" "abc"))
+(test #f (string-ci=? "" "abc"))
+(test #t (string-ci=? "abc" "aBc"))
+(test #f (string-ci=? "abc" "aBcD"))
+
+(test #f (string-ci<? "abc" "aBc"))
+(test #t (string-ci<? "abc" "aBcD"))
+(test #f (string-ci<? "ABCd" "aBc"))
+
+(test #f (string-ci>? "abc" "aBc"))
+(test #f (string-ci>? "abc" "aBcD"))
+(test #t (string-ci>? "ABCd" "aBc"))
+
+(test #t (string-ci<=? "abc" "aBc"))
+(test #t (string-ci<=? "abc" "aBcD"))
+(test #f (string-ci<=? "ABCd" "aBc"))
+
+(test #t (string-ci>=? "abc" "aBc"))
+(test #f (string-ci>=? "abc" "aBcD"))
+(test #t (string-ci>=? "ABCd" "aBc"))
+
+(test #t (string-ci=? "ΑΒΓ" "αβγ" "αβγ"))
+(test #f (string-ci<? "ΑΒΓ" "αβγ"))
+(test #f (string-ci>? "ΑΒΓ" "αβγ"))
+(test #t (string-ci<=? "ΑΒΓ" "αβγ"))
+(test #t (string-ci>=? "ΑΒΓ" "αβγ"))
+
+;; latin
+(test "ABC" (string-upcase "abc"))
+(test "ABC" (string-upcase "ABC"))
+(test "abc" (string-downcase "abc"))
+(test "abc" (string-downcase "ABC"))
+(test "abc" (string-foldcase "abc"))
+(test "abc" (string-foldcase "ABC"))
+
+;; cyrillic
+(test "ΑΒΓ" (string-upcase "αβγ"))
+(test "ΑΒΓ" (string-upcase "ΑΒΓ"))
+(test "αβγ" (string-downcase "αβγ"))
+(test "αβγ" (string-downcase "ΑΒΓ"))
+(test "αβγ" (string-foldcase "αβγ"))
+(test "αβγ" (string-foldcase "ΑΒΓ"))
+
+;; special cases
+(test "SSA" (string-upcase "ßa"))
+(test "ßa" (string-downcase "ßa"))
+(test "ssa" (string-downcase "SSA"))
+(test "maß" (string-downcase "Maß"))
+(test "mass" (string-foldcase "Maß"))
+(test "İ" (string-upcase "İ"))
+(test "i\x0307;" (string-downcase "İ"))
+(test "i\x0307;" (string-foldcase "İ"))
+(test "J̌" (string-upcase "ǰ"))
+(test "ſ" (string-downcase "ſ"))
+(test "s" (string-foldcase "ſ"))
+
+;; context-sensitive (final sigma)
+(test "ΓΛΏΣΣΑ" (string-upcase "γλώσσα"))
+(test "γλώσσα" (string-downcase "ΓΛΏΣΣΑ"))
+(test "γλώσσα" (string-foldcase "ΓΛΏΣΣΑ"))
+(test "ΜΈΛΟΣ" (string-upcase "μέλος"))
+(test #t (and (member (string-downcase "ΜΈΛΟΣ") '("μέλος" "μέλοσ")) #t))
+(test "μέλοσ" (string-foldcase "ΜΈΛΟΣ"))
+(test #t (and (member (string-downcase "ΜΈΛΟΣ ΕΝΌΣ")
+                      '("μέλος ενός" "μέλοσ ενόσ"))
+              #t))
+
+(test "" (substring "" 0 0))
+(test "" (substring "a" 0 0))
+(test "" (substring "abc" 1 1))
+(test "ab" (substring "abc" 0 2))
+(test "bc" (substring "abc" 1 3))
+
+(test "" (string-append ""))
+(test "" (string-append "" ""))
+(test "abc" (string-append "" "abc"))
+(test "abc" (string-append "abc" ""))
+(test "abcde" (string-append "abc" "de"))
+(test "abcdef" (string-append "abc" "de" "f"))
+
+(test '() (string->list ""))
+(test '(#\a) (string->list "a"))
+(test '(#\a #\b #\c) (string->list "abc"))
+(test '(#\a #\b #\c) (string->list "abc" 0))
+(test '(#\b #\c) (string->list "abc" 1))
+(test '(#\b #\c) (string->list "abc" 1 3))
+
+(test "" (list->string '()))
+(test "abc" (list->string '(#\a #\b #\c)))
+
+(test "" (string-copy ""))
+(test "" (string-copy "" 0))
+(test "" (string-copy "" 0 0))
+(test "abc" (string-copy "abc"))
+(test "abc" (string-copy "abc" 0))
+(test "bc" (string-copy "abc" 1))
+(test "b" (string-copy "abc" 1 2))
+(test "bc" (string-copy "abc" 1 3))
+
+(test "-----"
+    (let ((str (make-string 5 #\x))) (string-fill! str #\-) str))
+(test "xx---"
+    (let ((str (make-string 5 #\x))) (string-fill! str #\- 2) str))
+(test "xx-xx"
+    (let ((str (make-string 5 #\x))) (string-fill! str #\- 2 3) str))
+
+(test "a12de"
+    (let ((str (string-copy "abcde"))) (string-copy! str 1 "12345" 0 2) str))
+(test "-----"
+    (let ((str (make-string 5 #\x))) (string-copy! str 0 "-----") str))
+(test "---xx"
+    (let ((str (make-string 5 #\x))) (string-copy! str 0 "-----" 2) str))
+(test "xx---"
+    (let ((str (make-string 5 #\x))) (string-copy! str 2 "-----" 0 3) str))
+(test "xx-xx"
+    (let ((str (make-string 5 #\x))) (string-copy! str 2 "-----" 2 3) str))
+
+;; same source and dest
+(test "aabde"
+    (let ((str (string-copy "abcde"))) (string-copy! str 1 str 0 2) str))
+(test "abcab"
+    (let ((str (string-copy "abcde"))) (string-copy! str 3 str 0 2) str))
+
+(test-end)
+
+(test-begin "6.8 Vectors")
+
+(test #t (vector? #()))
+(test #t (vector? #(1 2 3)))
+(test #t (vector? '#(1 2 3)))
+
+(test 0 (vector-length (make-vector 0)))
+(test 1000 (vector-length (make-vector 1000)))
+
+(test #(0 (2 2 2 2) "Anna") '#(0 (2 2 2 2) "Anna"))
+
+(test #(a b c) (vector 'a 'b 'c))
+
+(test 8 (vector-ref '#(1 1 2 3 5 8 13 21) 5))
+(test 13 (vector-ref '#(1 1 2 3 5 8 13 21)
+            (let ((i (round (* 2 (acos -1)))))
+              (if (inexact? i)
+                  (exact i)
+                  i))))
+
+(test #(0 ("Sue" "Sue") "Anna") (let ((vec (vector 0 '(2 2 2 2) "Anna")))
+  (vector-set! vec 1 '("Sue" "Sue"))
+  vec))
+
+(test '(dah dah didah) (vector->list '#(dah dah didah)))
+(test '(dah didah) (vector->list '#(dah dah didah) 1))
+(test '(dah) (vector->list '#(dah dah didah) 1 2))
+(test #(dididit dah) (list->vector '(dididit dah)))
+
+(test #() (string->vector ""))
+(test #(#\A #\B #\C) (string->vector "ABC"))
+(test #(#\B #\C) (string->vector "ABC" 1))
+(test #(#\B) (string->vector "ABC" 1 2))
+
+(test "" (vector->string #()))
+(test "123" (vector->string #(#\1 #\2 #\3)))
+(test "23" (vector->string #(#\1 #\2 #\3) 1))
+(test "2" (vector->string #(#\1 #\2 #\3) 1 2))
+
+(test #() (vector-copy #()))
+(test #(a b c) (vector-copy #(a b c)))
+(test #(b c) (vector-copy #(a b c) 1))
+(test #(b) (vector-copy #(a b c) 1 2))
+
+(test #() (vector-append #()))
+(test #() (vector-append #() #()))
+(test #(a b c) (vector-append #() #(a b c)))
+(test #(a b c) (vector-append #(a b c) #()))
+(test #(a b c d e) (vector-append #(a b c) #(d e)))
+(test #(a b c d e f) (vector-append #(a b c) #(d e) #(f)))
+
+(test #(1 2 smash smash 5)
+    (let ((vec (vector 1 2 3 4 5))) (vector-fill! vec 'smash 2 4) vec))
+(test #(x x x x x)
+    (let ((vec (vector 1 2 3 4 5))) (vector-fill! vec 'x) vec))
+(test #(1 2 x x x)
+    (let ((vec (vector 1 2 3 4 5))) (vector-fill! vec 'x 2) vec))
+(test #(1 2 x 4 5)
+    (let ((vec (vector 1 2 3 4 5))) (vector-fill! vec 'x 2 3) vec))
+
+(test #(1 a b 4 5)
+    (let ((vec (vector 1 2 3 4 5))) (vector-copy! vec 1 #(a b c d e) 0 2) vec))
+(test #(a b c d e)
+    (let ((vec (vector 1 2 3 4 5))) (vector-copy! vec 0 #(a b c d e)) vec))
+(test #(c d e 4 5)
+    (let ((vec (vector 1 2 3 4 5))) (vector-copy! vec 0 #(a b c d e) 2) vec))
+(test #(1 2 a b c)
+    (let ((vec (vector 1 2 3 4 5))) (vector-copy! vec 2 #(a b c d e) 0 3) vec))
+(test #(1 2 c 4 5)
+    (let ((vec (vector 1 2 3 4 5))) (vector-copy! vec 2 #(a b c d e) 2 3) vec))
+
+;; same source and dest
+(test #(1 1 2 4 5)
+    (let ((vec (vector 1 2 3 4 5))) (vector-copy! vec 1 vec 0 2) vec))
+(test #(1 2 3 1 2)
+    (let ((vec (vector 1 2 3 4 5))) (vector-copy! vec 3 vec 0 2) vec))
+
+(test-end)
+
+(test-begin "6.9 Bytevectors")
+
+(test #t (bytevector? #u8()))
+(test #t (bytevector? #u8(0 1 2)))
+(test #f (bytevector? #()))
+(test #f (bytevector? #(0 1 2)))
+(test #f (bytevector? '()))
+(test #t (bytevector? (make-bytevector 0)))
+
+(test 0 (bytevector-length (make-bytevector 0)))
+(test 1024 (bytevector-length (make-bytevector 1024)))
+(test 1024 (bytevector-length (make-bytevector 1024 255)))
+
+(test 3 (bytevector-length (bytevector 0 1 2)))
+
+(test 0 (bytevector-u8-ref (bytevector 0 1 2) 0))
+(test 1 (bytevector-u8-ref (bytevector 0 1 2) 1))
+(test 2 (bytevector-u8-ref (bytevector 0 1 2) 2))
+
+(test #u8(0 255 2)
+    (let ((bv (bytevector 0 1 2))) (bytevector-u8-set! bv 1 255) bv))
+
+(test #u8() (bytevector-copy #u8()))
+(test #u8(0 1 2) (bytevector-copy #u8(0 1 2)))
+(test #u8(1 2) (bytevector-copy #u8(0 1 2) 1))
+(test #u8(1) (bytevector-copy #u8(0 1 2) 1 2))
+
+(test #u8(1 6 7 4 5)
+    (let ((bv (bytevector 1 2 3 4 5)))
+      (bytevector-copy! bv 1 #u8(6 7 8 9 10) 0 2)
+      bv))
+(test #u8(6 7 8 9 10)
+    (let ((bv (bytevector 1 2 3 4 5)))
+      (bytevector-copy! bv 0 #u8(6 7 8 9 10))
+      bv))
+(test #u8(8 9 10 4 5)
+    (let ((bv (bytevector 1 2 3 4 5)))
+      (bytevector-copy! bv 0 #u8(6 7 8 9 10) 2)
+      bv))
+(test #u8(1 2 6 7 8)
+    (let ((bv (bytevector 1 2 3 4 5)))
+      (bytevector-copy! bv 2 #u8(6 7 8 9 10) 0 3)
+      bv))
+(test #u8(1 2 8 4 5)
+    (let ((bv (bytevector 1 2 3 4 5)))
+      (bytevector-copy! bv 2 #u8(6 7 8 9 10) 2 3)
+      bv))
+
+;; same source and dest
+(test #u8(1 1 2 4 5)
+    (let ((bv (bytevector 1 2 3 4 5)))
+      (bytevector-copy! bv 1 bv 0 2)
+      bv))
+(test #u8(1 2 3 1 2)
+    (let ((bv (bytevector 1 2 3 4 5)))
+      (bytevector-copy! bv 3 bv 0 2)
+      bv))
+
+(test #u8() (bytevector-append #u8()))
+(test #u8() (bytevector-append #u8() #u8()))
+(test #u8(0 1 2) (bytevector-append #u8() #u8(0 1 2)))
+(test #u8(0 1 2) (bytevector-append #u8(0 1 2) #u8()))
+(test #u8(0 1 2 3 4) (bytevector-append #u8(0 1 2) #u8(3 4)))
+(test #u8(0 1 2 3 4 5) (bytevector-append #u8(0 1 2) #u8(3 4) #u8(5)))
+
+(test "ABC" (utf8->string #u8(#x41 #x42 #x43)))
+(test "ABC" (utf8->string #u8(0 #x41 #x42 #x43) 1))
+(test "ABC" (utf8->string #u8(0 #x41  #x42 #x43 0) 1 4))
+(test "λ" (utf8->string #u8(0 #xCE #xBB 0) 1 3))
+(test #u8(#x41 #x42 #x43) (string->utf8 "ABC"))
+(test #u8(#x42 #x43) (string->utf8 "ABC" 1))
+(test #u8(#x42) (string->utf8 "ABC" 1 2))
+(test #u8(#xCE #xBB) (string->utf8 "λ"))
+
+(test-end)
+
+(test-begin "6.10 Control Features")
+
+(test #t (procedure? car))
+(test #f (procedure? 'car))
+(test #t (procedure? (lambda (x) (* x x))))
+(test #f (procedure? '(lambda (x) (* x x))))
+(test #t (call-with-current-continuation procedure?))
+
+(test 7 (apply + (list 3 4)))
+(test 7 (apply + 3 4 (list)))
+(test-error (apply +)) ;; not enough args
+(test-error (apply + 3)) ;; final arg not a list
+(test-error (apply + 3 4)) ;; final arg not a list
+(test-error (apply + '(2 3 . 4))) ;; final arg is improper
+
+
+(define compose
+  (lambda (f g)
+    (lambda args
+      (f (apply g args)))))
+(test '(30 0)
+    (call-with-values (lambda () ((compose exact-integer-sqrt *) 12 75))
+      list))
+
+(test '(b e h) (map cadr '((a b) (d e) (g h))))
+
+(test '(1 4 27 256 3125) (map (lambda (n) (expt n n)) '(1 2 3 4 5)))
+
+(test '(5 7 9) (map + '(1 2 3) '(4 5 6 7)))
+
+(test #t
+    (let ((res (let ((count 0))
+                 (map (lambda (ignored)
+                        (set! count (+ count 1))
+                        count)
+                      '(a b)))))
+      (or (equal? res '(1 2))
+          (equal? res '(2 1)))))
+
+(test '(10 200 3000 40 500 6000)
+    (let ((ls1 (list 10 100 1000))
+          (ls2 (list 1 2 3 4 5 6)))
+      (set-cdr! (cddr ls1) ls1)
+      (map * ls1 ls2)))
+
+(test "abdegh" (string-map char-foldcase "AbdEgH"))
+
+(test "IBM" (string-map
+ (lambda (c)
+   (integer->char (+ 1 (char->integer c))))
+ "HAL"))
+
+(test "StUdLyCaPs"
+    (string-map
+     (lambda (c k) (if (eqv? k #\u) (char-upcase c) (char-downcase c)))
+     "studlycaps xxx"
+     "ululululul"))
+
+(test #(b e h) (vector-map cadr '#((a b) (d e) (g h))))
+
+(test #(1 4 27 256 3125)
+    (vector-map (lambda (n) (expt n n))
+                '#(1 2 3 4 5)))
+
+(test #(5 7 9) (vector-map + '#(1 2 3) '#(4 5 6 7)))
+
+(test #t
+    (let ((res (let ((count 0))
+                 (vector-map
+                  (lambda (ignored)
+                    (set! count (+ count 1))
+                    count)
+                  '#(a b)))))
+      (or (equal? res #(1 2))
+          (equal? res #(2 1)))))
+
+(test #(0 1 4 9 16)
+    (let ((v (make-vector 5)))
+      (for-each (lambda (i)
+                  (vector-set! v i (* i i)))
+                '(0 1 2 3 4))
+      v))
+
+(test 9750
+    (let ((ls1 (list 10 100 1000))
+          (ls2 (list 1 2 3 4 5 6))
+          (count 0))
+      (set-cdr! (cddr ls1) ls1)
+      (for-each (lambda (x y) (set! count (+ count (* x y)))) ls2 ls1)
+      count))
+
+(test '(101 100 99 98 97)
+    (let ((v '()))
+      (string-for-each
+       (lambda (c) (set! v (cons (char->integer c) v)))
+       "abcde")
+      v))
+
+(test '(0 1 4 9 16) (let ((v (make-list 5)))
+  (vector-for-each
+   (lambda (i) (list-set! v i (* i i)))
+   '#(0 1 2 3 4))
+  v))
+
+(test -3 (call-with-current-continuation
+  (lambda (exit)
+    (for-each (lambda (x)
+                (if (negative? x)
+                    (exit x)))
+              '(54 0 37 -3 245 19))
+    #t)))
+(define list-length
+  (lambda (obj)
+    (call-with-current-continuation
+      (lambda (return)
+        (letrec ((r
+                  (lambda (obj)
+                    (cond ((null? obj) 0)
+                          ((pair? obj)
+                           (+ (r (cdr obj)) 1))
+                          (else (return #f))))))
+          (r obj))))))
+
+(test 4 (list-length '(1 2 3 4)))
+
+(test #f (list-length '(a b . c)))
+
+(test 5
+    (call-with-values (lambda () (values 4 5))
+      (lambda (a b) b)))
+
+(test -1 (call-with-values * -))
+
+(test '(connect talk1 disconnect
+        connect talk2 disconnect)
+    (let ((path '())
+          (c #f))
+      (let ((add (lambda (s)
+                   (set! path (cons s path)))))
+        (dynamic-wind
+          (lambda () (add 'connect))
+          (lambda ()
+            (add (call-with-current-continuation
+                  (lambda (c0)
+                    (set! c c0)
+                    'talk1))))
+          (lambda () (add 'disconnect)))
+        (if (< (length path) 4)
+            (c 'talk2)
+            (reverse path)))))
+
+(test-end)
+
+(test-begin "6.11 Exceptions")
+
+(test 65
+    (with-exception-handler
+     (lambda (con) 42)
+     (lambda ()
+       (+ (raise-continuable "should be a number")
+          23))))
+
+(test #t
+    (error-object? (guard (exn (else exn)) (error "BOOM!" 1 2 3))))
+(test "BOOM!"
+    (error-object-message (guard (exn (else exn)) (error "BOOM!" 1 2 3))))
+(test '(1 2 3)
+    (error-object-irritants (guard (exn (else exn)) (error "BOOM!" 1 2 3))))
+
+(test #f
+    (file-error? (guard (exn (else exn)) (error "BOOM!"))))
+(test #t
+    (file-error? (guard (exn (else exn)) (open-input-file " no such file "))))
+
+(test #f
+    (read-error? (guard (exn (else exn)) (error "BOOM!"))))
+(test #t
+    (read-error? (guard (exn (else exn)) (read (open-input-string ")")))))
+(test #t
+    (read-error? (guard (exn (else exn)) (read (open-input-string "\"")))))
+
+(define something-went-wrong #f)
+(define (test-exception-handler-1 v)
+  (call-with-current-continuation
+   (lambda (k)
+     (with-exception-handler
+      (lambda (x)
+        (set! something-went-wrong (list "condition: " x))
+        (k 'exception))
+      (lambda ()
+        (+ 1 (if (> v 0) (+ v 100) (raise 'an-error))))))))
+(test 106 (test-exception-handler-1 5))
+(test #f something-went-wrong)
+(test 'exception (test-exception-handler-1 -1))
+(test '("condition: " an-error) something-went-wrong)
+
+(set! something-went-wrong #f)
+(define (test-exception-handler-2 v)
+  (guard (ex (else 'caught-another-exception))
+    (with-exception-handler
+     (lambda (x)
+       (set! something-went-wrong #t)
+       (list "exception:" x))
+     (lambda ()
+       (+ 1 (if (> v 0) (+ v 100) (raise 'an-error)))))))
+(test 106 (test-exception-handler-2 5))
+(test #f something-went-wrong)
+(test 'caught-another-exception (test-exception-handler-2 -1))
+(test #t something-went-wrong)
+
+;; Based on an example from R6RS-lib section 7.1 Exceptions.
+;; R7RS section 6.11 Exceptions has a simplified version.
+(let* ((out (open-output-string))
+       (value (with-exception-handler
+               (lambda (con)
+                 (cond
+                  ((not (list? con))
+                   (raise con))
+                  ((list? con)
+                   (display (car con) out))
+                  (else
+                   (display "a warning has been issued" out)))
+                 42)
+               (lambda ()
+                 (+ (raise-continuable
+                     (list "should be a number"))
+                    23)))))
+  (test "should be a number" (get-output-string out))
+  (test 65 value))
+
+;; From SRFI-34 "Examples" section - #3
+(define (test-exception-handler-3 v out)
+  (guard (condition
+          (else
+           (display "condition: " out)
+           (write condition out)
+           (display #\! out)
+           'exception))
+         (+ 1 (if (= v 0) (raise 'an-error) (/ 10 v)))))
+(let* ((out (open-output-string))
+       (value (test-exception-handler-3 0 out)))
+  (test 'exception value)
+  (test "condition: an-error!" (get-output-string out)))
+
+(define (test-exception-handler-4 v out)
+  (call-with-current-continuation
+   (lambda (k)
+     (with-exception-handler
+      (lambda (x)
+        (display "reraised " out)
+        (write x out) (display #\! out)
+        (k 'zero))
+      (lambda ()
+        (guard (condition
+                ((positive? condition)
+                 'positive)
+                ((negative? condition)
+                 'negative))
+          (raise v)))))))
+
+;; From SRFI-34 "Examples" section - #5
+(let* ((out (open-output-string))
+       (value (test-exception-handler-4 1 out)))
+  (test "" (get-output-string out))
+  (test 'positive value))
+;; From SRFI-34 "Examples" section - #6
+(let* ((out (open-output-string))
+       (value (test-exception-handler-4 -1 out)))
+  (test "" (get-output-string out))
+  (test 'negative value))
+;; From SRFI-34 "Examples" section - #7
+(let* ((out (open-output-string))
+       (value (test-exception-handler-4 0 out)))
+  (test "reraised 0!" (get-output-string out))
+  (test 'zero value))
+
+;; From SRFI-34 "Examples" section - #8
+(test 42
+    (guard (condition
+            ((assq 'a condition) => cdr)
+            ((assq 'b condition)))
+      (raise (list (cons 'a 42)))))
+
+;; From SRFI-34 "Examples" section - #9
+(test '(b . 23)
+    (guard (condition
+            ((assq 'a condition) => cdr)
+            ((assq 'b condition)))
+      (raise (list (cons 'b 23)))))
+
+(test 'caught-d
+    (guard (condition
+            ((assq 'c condition) 'caught-c)
+            ((assq 'd condition) 'caught-d))
+      (list
+       (sqrt 8)
+       (guard (condition
+               ((assq 'a condition) => cdr)
+               ((assq 'b condition)))
+         (raise (list (cons 'd 24)))))))
+
+(test-end)
+
+(test-begin "6.12 Environments and evaluation")
+
+;; (test 21 (eval '(* 7 3) (scheme-report-environment 5)))
+
+(test 20
+    (let ((f (eval '(lambda (f x) (f x x)) (null-environment 5))))
+      (f + 10)))
+
+(test 1024 (eval '(expt 2 10) (environment '(scheme base))))
+;; (sin 0) may return exact number
+(test 0.0 (inexact (eval '(sin 0) (environment '(scheme inexact)))))
+;; ditto
+(test 1024.0 (eval '(+ (expt 2 10) (inexact (sin 0)))
+                   (environment '(scheme base) '(scheme inexact))))
+
+(test-end)
+
+(test-begin "6.13 Input and output")
+
+(test #t (port? (current-input-port)))
+(test #t (input-port? (current-input-port)))
+(test #t (output-port? (current-output-port)))
+(test #t (output-port? (current-error-port)))
+(test #t (input-port? (open-input-string "abc")))
+(test #t (output-port? (open-output-string)))
+
+(test #t (textual-port? (open-input-string "abc")))
+(test #t (textual-port? (open-output-string)))
+(test #t (binary-port? (open-input-bytevector #u8(0 1 2))))
+(test #t (binary-port? (open-output-bytevector)))
+
+(test #t (input-port-open? (open-input-string "abc")))
+(test #t (output-port-open? (open-output-string)))
+
+(test #f
+    (let ((in (open-input-string "abc")))
+      (close-input-port in)
+      (input-port-open? in)))
+
+(test #f
+    (let ((out (open-output-string)))
+      (close-output-port out)
+      (output-port-open? out)))
+
+(test #f
+    (let ((out (open-output-string)))
+      (close-port out)
+      (output-port-open? out)))
+
+(test 'error
+    (let ((in (open-input-string "abc")))
+      (close-input-port in)
+      (guard (exn (else 'error)) (read-char in))))
+
+(test 'error
+    (let ((out (open-output-string)))
+      (close-output-port out)
+      (guard (exn (else 'error)) (write-char #\c out))))
+
+(test #t (eof-object? (eof-object)))
+(test #t (eof-object? (read (open-input-string ""))))
+(test #t (char-ready? (open-input-string "42")))
+(test 42 (read (open-input-string " 42 ")))
+
+(test #t (eof-object? (read-char (open-input-string ""))))
+(test #\a (read-char (open-input-string "abc")))
+
+(test #t (eof-object? (read-line (open-input-string ""))))
+(test "abc" (read-line (open-input-string "abc")))
+(test "abc" (read-line (open-input-string "abc\ndef\n")))
+
+(test #t (eof-object? (read-string 3 (open-input-string ""))))
+(test "abc" (read-string 3 (open-input-string "abcd")))
+(test "abc" (read-string 3 (open-input-string "abc\ndef\n")))
+
+(let ((in (open-input-string (string #\x10F700 #\x10F701 #\x10F702))))
+  (let* ((c0 (peek-char in))
+         (c1 (read-char in))
+         (c2 (read-char in))
+         (c3 (read-char in)))
+    (test #\x10F700 c0)
+    (test #\x10F700 c1)
+    (test #\x10F701 c2)
+    (test #\x10F702 c3)))
+
+(test (string #\x10F700)
+    (let ((out (open-output-string)))
+      (write-char #\x10F700 out)
+      (get-output-string out)))
+
+(test "abc"
+    (let ((out (open-output-string)))
+      (write 'abc out)
+      (get-output-string out)))
+
+(test "abc def"
+    (let ((out (open-output-string)))
+      (display "abc def" out)
+      (get-output-string out)))
+
+(test "abc"
+    (let ((out (open-output-string)))
+      (display #\a out)
+      (display "b" out)
+      (display #\c out)
+      (get-output-string out)))
+
+(test #t
+      (let* ((out (open-output-string))
+             (r (begin (newline out) (get-output-string out))))
+        (or (equal? r "\n") (equal? r "\r\n"))))
+
+(test "abc def"
+    (let ((out (open-output-string)))
+      (write-string "abc def" out)
+      (get-output-string out)))
+
+(test "def"
+    (let ((out (open-output-string)))
+      (write-string "abc def" out 4)
+      (get-output-string out)))
+
+(test "c d"
+    (let ((out (open-output-string)))
+      (write-string "abc def" out 2 5)
+      (get-output-string out)))
+
+(test ""
+  (let ((out (open-output-string)))
+    (flush-output-port out)
+    (get-output-string out)))
+
+(test #t (eof-object? (read-u8 (open-input-bytevector #u8()))))
+(test 1 (read-u8 (open-input-bytevector #u8(1 2 3))))
+
+(test #t (eof-object? (read-bytevector 3 (open-input-bytevector #u8()))))
+(test #t (u8-ready? (open-input-bytevector #u8(1))))
+(test #u8(1) (read-bytevector 3 (open-input-bytevector #u8(1))))
+(test #u8(1 2) (read-bytevector 3 (open-input-bytevector #u8(1 2))))
+(test #u8(1 2 3) (read-bytevector 3 (open-input-bytevector #u8(1 2 3))))
+(test #u8(1 2 3) (read-bytevector 3 (open-input-bytevector #u8(1 2 3 4))))
+
+(test #t
+    (let ((bv (bytevector 1 2 3 4 5)))
+      (eof-object? (read-bytevector! bv (open-input-bytevector #u8())))))
+
+(test #u8(6 7 8 9 10)
+  (let ((bv (bytevector 1 2 3 4 5)))
+    (read-bytevector! bv (open-input-bytevector #u8(6 7 8 9 10)) 0 5)
+    bv))
+
+(test #u8(6 7 8 4 5)
+  (let ((bv (bytevector 1 2 3 4 5)))
+    (read-bytevector! bv (open-input-bytevector #u8(6 7 8 9 10)) 0 3)
+    bv))
+
+(test #u8(1 2 3 6 5)
+  (let ((bv (bytevector 1 2 3 4 5)))
+    (read-bytevector! bv (open-input-bytevector #u8(6 7 8 9 10)) 3 4)
+    bv))
+
+(test #u8(1 2 3)
+  (let ((out (open-output-bytevector)))
+    (write-u8 1 out)
+    (write-u8 2 out)
+    (write-u8 3 out)
+    (get-output-bytevector out)))
+
+(test #u8(1 2 3 4 5)
+  (let ((out (open-output-bytevector)))
+    (write-bytevector #u8(1 2 3 4 5) out)
+    (get-output-bytevector out)))
+
+(test #u8(3 4 5)
+  (let ((out (open-output-bytevector)))
+    (write-bytevector #u8(1 2 3 4 5) out 2)
+    (get-output-bytevector out)))
+
+(test #u8(3 4)
+  (let ((out (open-output-bytevector)))
+    (write-bytevector #u8(1 2 3 4 5) out 2 4)
+    (get-output-bytevector out)))
+
+(test #u8()
+  (let ((out (open-output-bytevector)))
+    (flush-output-port out)
+    (get-output-bytevector out)))
+
+(test #t
+    (and (member
+          (let ((out (open-output-string))
+                (x (list 1)))
+            (set-cdr! x x)
+            (write x out)
+            (get-output-string out))
+          ;; labels not guaranteed to be 0 indexed, spacing may differ
+          '("#0=(1 . #0#)" "#1=(1 . #1#)"))
+         #t))
+
+(test "((1 2 3) (1 2 3))"
+    (let ((out (open-output-string))
+          (x (list 1 2 3)))
+      (write (list x x) out)
+      (get-output-string out)))
+
+(test "((1 2 3) (1 2 3))"
+    (let ((out (open-output-string))
+          (x (list 1 2 3)))
+      (write-simple (list x x) out)
+      (get-output-string out)))
+
+(test #t
+    (and (member (let ((out (open-output-string))
+                       (x (list 1 2 3)))
+                   (write-shared (list x x) out)
+                   (get-output-string out))
+                 '("(#0=(1 2 3) #0#)" "(#1=(1 2 3) #1#)"))
+         #t))
+
+(test-begin "Read syntax")
+
+;; check reading boolean followed by eof
+(test #t (read (open-input-string "#t")))
+(test #t (read (open-input-string "#true")))
+(test #f (read (open-input-string "#f")))
+(test #f (read (open-input-string "#false")))
+(define (read2 port)
+  (let* ((o1 (read port)) (o2 (read port)))
+    (cons o1 o2)))
+;; check reading boolean followed by delimiter
+(test '(#t . (5)) (read2 (open-input-string "#t(5)")))
+(test '(#t . 6) (read2 (open-input-string "#true 6 ")))
+(test '(#f . 7) (read2 (open-input-string "#f 7")))
+(test '(#f . "8") (read2 (open-input-string "#false\"8\"")))
+
+(test '() (read (open-input-string "()")))
+(test '(1 2) (read (open-input-string "(1 2)")))
+(test '(1 . 2) (read (open-input-string "(1 . 2)")))
+(test '(1 2) (read (open-input-string "(1 . (2))")))
+(test '(1 2 3 4 5) (read (open-input-string "(1 . (2 3 4 . (5)))")))
+(test '1 (cadr (read (open-input-string "#0=(1 . #0#)"))))
+(test '(1 2 3) (cadr (read (open-input-string "(#0=(1 2 3) #0#)"))))
+
+(test '(quote (1 2)) (read (open-input-string "'(1 2)")))
+(test '(quote (1 (unquote 2))) (read (open-input-string "'(1 ,2)")))
+(test '(quote (1 (unquote-splicing 2))) (read (open-input-string "'(1 ,@2)")))
+(test '(quasiquote (1 (unquote 2))) (read (open-input-string "`(1 ,2)")))
+
+(test #() (read (open-input-string "#()")))
+(test #(a b) (read (open-input-string "#(a b)")))
+
+(test #u8() (read (open-input-string "#u8()")))
+(test #u8(0 1) (read (open-input-string "#u8(0 1)")))
+
+(test 'abc (read (open-input-string "abc")))
+(test 'abc (read (open-input-string "abc def")))
+(test 'ABC (read (open-input-string "ABC")))
+(test 'Hello (read (open-input-string "|H\\x65;llo|")))
+
+(test 'abc (read (open-input-string "#!fold-case ABC")))
+(test 'ABC (read (open-input-string "#!fold-case #!no-fold-case ABC")))
+
+(test 'def (read (open-input-string "#; abc def")))
+(test 'def (read (open-input-string "; abc \ndef")))
+(test 'def (read (open-input-string "#| abc |# def")))
+(test 'ghi (read (open-input-string "#| abc #| def |# |# ghi")))
+(test 'ghi (read (open-input-string "#; ; abc\n def ghi")))
+(test '(abs -16) (read (open-input-string "(#;sqrt abs -16)")))
+(test '(a d) (read (open-input-string "(a #; #;b c d)")))
+(test '(a e) (read (open-input-string "(a #;(b #;c d) e)")))
+(test '(a . c) (read (open-input-string "(a . #;b c)")))
+(test '(a . b) (read (open-input-string "(a . b #;c)")))
+
+(define (test-read-error str)
+  (test-assert str
+      (guard (exn (else #t))
+        (read (open-input-string str))
+        #f)))
+
+(test-read-error "(#;a . b)")
+(test-read-error "(a . #;b)")
+(test-read-error "(a #;. b)")
+(test-read-error "(#;x #;y . z)")
+(test-read-error "(#; #;x #;y . z)")
+(test-read-error "(#; #;x . z)")
+
+(test #\a (read (open-input-string "#\\a")))
+(test #\space (read (open-input-string "#\\space")))
+(test 0 (char->integer (read (open-input-string "#\\null"))))
+(test 7 (char->integer (read (open-input-string "#\\alarm"))))
+(test 8 (char->integer (read (open-input-string "#\\backspace"))))
+(test 9 (char->integer (read (open-input-string "#\\tab"))))
+(test 10 (char->integer (read (open-input-string "#\\newline"))))
+(test 13 (char->integer (read (open-input-string "#\\return"))))
+(test #x7F (char->integer (read (open-input-string "#\\delete"))))
+(test #x1B (char->integer (read (open-input-string "#\\escape"))))
+(test #x03BB (char->integer (read (open-input-string "#\\λ"))))
+(test #x03BB (char->integer (read (open-input-string "#\\x03BB"))))
+
+(test "abc" (read (open-input-string "\"abc\"")))
+(test "abc" (read (open-input-string "\"abc\" \"def\"")))
+(test "ABC" (read (open-input-string "\"ABC\"")))
+(test "Hello" (read (open-input-string "\"H\\x65;llo\"")))
+(test 7 (char->integer (string-ref (read (open-input-string "\"\\a\"")) 0)))
+(test 8 (char->integer (string-ref (read (open-input-string "\"\\b\"")) 0)))
+(test 9 (char->integer (string-ref (read (open-input-string "\"\\t\"")) 0)))
+(test 10 (char->integer (string-ref (read (open-input-string "\"\\n\"")) 0)))
+(test 13 (char->integer (string-ref (read (open-input-string "\"\\r\"")) 0)))
+(test #x22 (char->integer (string-ref (read (open-input-string "\"\\\"\"")) 0)))
+(test #x7C (char->integer (string-ref (read (open-input-string "\"\\|\"")) 0)))
+(test "line 1\nline 2\n" (read (open-input-string "\"line 1\nline 2\n\"")))
+(test "line 1continued\n" (read (open-input-string "\"line 1\\\ncontinued\n\"")))
+(test "line 1continued\n" (read (open-input-string "\"line 1\\ \ncontinued\n\"")))
+(test "line 1continued\n" (read (open-input-string "\"line 1\\\n continued\n\"")))
+(test "line 1continued\n" (read (open-input-string "\"line 1\\ \t \n \t continued\n\"")))
+(test "line 1\n\nline 3\n" (read (open-input-string "\"line 1\\ \t \n \t \n\nline 3\n\"")))
+(test #x03BB (char->integer (string-ref (read (open-input-string "\"\\x03BB;\"")) 0)))
+
+(define-syntax test-write-syntax
+  (syntax-rules ()
+    ((test-write-syntax expect-str obj-expr)
+     (let ((out (open-output-string)))
+       (write obj-expr out)
+       (test expect-str (get-output-string out))))))
+
+(test-write-syntax "|.|" '|.|)
+(test-write-syntax "|a b|" '|a b|)
+(test-write-syntax "|,a|" '|,a|)
+(test-write-syntax "|\"|" '|\"|)
+(test-write-syntax "|\\||" '|\||)
+(test-write-syntax "||" '||)
+(test-write-syntax "|\\\\123|" '|\\123|)
+(test-write-syntax "a" '|a|)
+;; (test-write-syntax "a.b" '|a.b|)
+(test-write-syntax "|2|" '|2|)
+(test-write-syntax "|+3|" '|+3|)
+(test-write-syntax "|-.4|" '|-.4|)
+(test-write-syntax "|+i|" '|+i|)
+(test-write-syntax "|-i|" '|-i|)
+(test-write-syntax "|+inf.0|" '|+inf.0|)
+(test-write-syntax "|-inf.0|" '|-inf.0|)
+(test-write-syntax "|+nan.0|" '|+nan.0|)
+(test-write-syntax "|+NaN.0|" '|+NaN.0|)
+(test-write-syntax "|+NaN.0abc|" '|+NaN.0abc|)
+
+(test-end)
+
+(test-begin "Numeric syntax")
+
+;; Numeric syntax adapted from Peter Bex's tests.
+;;
+;; These are updated to R7RS, using string ports instead of
+;; string->number, and "error" tests removed because implementations
+;; are free to provide their own numeric extensions.  Currently all
+;; tests are run by default - need to cond-expand and test for
+;; infinities and -0.0.
+
+(define-syntax test-numeric-syntax
+  (syntax-rules ()
+    ((test-numeric-syntax str expect strs ...)
+     (let* ((z (read (open-input-string str)))
+            (out (open-output-string))
+            (z-str (begin (write z out) (get-output-string out))))
+       (test expect (values z))
+       (test #t (and (member z-str '(str strs ...)) #t))))))
+
+;; Each test is of the form:
+;;
+;;   (test-numeric-syntax input-str expected-value expected-write-values ...)
+;;
+;; where the input should be eqv? to the expected-value, and the
+;; written output the same as any of the expected-write-values.  The
+;; form
+;;
+;;   (test-numeric-syntax input-str expected-value)
+;;
+;; is a shorthand for
+;;
+;;   (test-numeric-syntax input-str expected-value (input-str))
+
+;; Simple
+(test-numeric-syntax "1" 1)
+(test-numeric-syntax "+1" 1 "1")
+(test-numeric-syntax "-1" -1)
+(test-numeric-syntax "#i1" 1.0 "1.0" "1.")
+(test-numeric-syntax "#I1" 1.0 "1.0" "1.")
+(test-numeric-syntax "#i-1" -1.0 "-1.0" "-1.")
+;; Decimal
+(test-numeric-syntax "1.0" 1.0 "1.0" "1.")
+(test-numeric-syntax "1." 1.0 "1.0" "1.")
+(test-numeric-syntax ".1" 0.1 "0.1" "100.0e-3")
+(test-numeric-syntax "-.1" -0.1 "-0.1" "-100.0e-3")
+;; Some Schemes don't allow negative zero. This is okay with the standard
+(test-numeric-syntax "-.0" -0.0 "-0." "-0.0" "0.0" "0." ".0")
+(test-numeric-syntax "-0." -0.0 "-.0" "-0.0" "0.0" "0." ".0")
+(test-numeric-syntax "#i1.0" 1.0 "1.0" "1.")
+(test-numeric-syntax "#e1.0" 1 "1")
+(test-numeric-syntax "#e-.0" 0 "0")
+(test-numeric-syntax "#e-0." 0 "0")
+;; Decimal notation with suffix
+(test-numeric-syntax "1e2" 100.0 "100.0" "100.")
+(test-numeric-syntax "1E2" 100.0 "100.0" "100.")
+(test-numeric-syntax "1s2" 100.0 "100.0" "100.")
+(test-numeric-syntax "1S2" 100.0 "100.0" "100.")
+(test-numeric-syntax "1f2" 100.0 "100.0" "100.")
+(test-numeric-syntax "1F2" 100.0 "100.0" "100.")
+(test-numeric-syntax "1d2" 100.0 "100.0" "100.")
+(test-numeric-syntax "1D2" 100.0 "100.0" "100.")
+(test-numeric-syntax "1l2" 100.0 "100.0" "100.")
+(test-numeric-syntax "1L2" 100.0 "100.0" "100.")
+;; NaN, Inf
+(test-numeric-syntax "+nan.0" +nan.0 "+nan.0" "+NaN.0")
+(test-numeric-syntax "+NAN.0" +nan.0 "+nan.0" "+NaN.0")
+(test-numeric-syntax "+inf.0" +inf.0 "+inf.0" "+Inf.0")
+(test-numeric-syntax "+InF.0" +inf.0 "+inf.0" "+Inf.0")
+(test-numeric-syntax "-inf.0" -inf.0 "-inf.0" "-Inf.0")
+(test-numeric-syntax "-iNF.0" -inf.0 "-inf.0" "-Inf.0")
+(test-numeric-syntax "#i+nan.0" +nan.0 "+nan.0" "+NaN.0")
+(test-numeric-syntax "#i+inf.0" +inf.0 "+inf.0" "+Inf.0")
+(test-numeric-syntax "#i-inf.0" -inf.0 "-inf.0" "-Inf.0")
+;; Exact ratios
+(test-numeric-syntax "1/2" (/ 1 2))
+(test-numeric-syntax "#e1/2" (/ 1 2) "1/2")
+(test-numeric-syntax "10/2" 5 "5")
+(test-numeric-syntax "-1/2" (- (/ 1 2)))
+(test-numeric-syntax "0/10" 0 "0")
+(test-numeric-syntax "#e0/10" 0 "0")
+(test-numeric-syntax "#i3/2" (/ 3.0 2.0) "1.5")
+;; Exact complex
+(test-numeric-syntax "1+2i" (make-rectangular 1 2))
+(test-numeric-syntax "1+2I" (make-rectangular 1 2) "1+2i")
+(test-numeric-syntax "1-2i" (make-rectangular 1 -2))
+(test-numeric-syntax "-1+2i" (make-rectangular -1 2))
+(test-numeric-syntax "-1-2i" (make-rectangular -1 -2))
+(test-numeric-syntax "+i" (make-rectangular 0 1) "+i" "+1i" "0+i" "0+1i")
+(test-numeric-syntax "0+i" (make-rectangular 0 1) "+i" "+1i" "0+i" "0+1i")
+(test-numeric-syntax "0+1i" (make-rectangular 0 1) "+i" "+1i" "0+i" "0+1i")
+(test-numeric-syntax "-i" (make-rectangular 0 -1) "-i" "-1i" "0-i" "0-1i")
+(test-numeric-syntax "0-i" (make-rectangular 0 -1) "-i" "-1i" "0-i" "0-1i")
+(test-numeric-syntax "0-1i" (make-rectangular 0 -1) "-i" "-1i" "0-i" "0-1i")
+(test-numeric-syntax "+2i" (make-rectangular 0 2) "2i" "+2i" "0+2i")
+(test-numeric-syntax "-2i" (make-rectangular 0 -2) "-2i" "0-2i")
+;; Decimal-notation complex numbers (rectangular notation)
+(test-numeric-syntax "1.0+2i" (make-rectangular 1.0 2) "1.0+2.0i" "1.0+2i" "1.+2i" "1.+2.i")
+(test-numeric-syntax "1+2.0i" (make-rectangular 1 2.0) "1.0+2.0i" "1+2.0i" "1.+2.i" "1+2.i")
+(test-numeric-syntax "1e2+1.0i" (make-rectangular 100.0 1.0) "100.0+1.0i" "100.+1.i")
+(test-numeric-syntax "1s2+1.0i" (make-rectangular 100.0 1.0) "100.0+1.0i" "100.+1.i")
+(test-numeric-syntax "1.0+1e2i" (make-rectangular 1.0 100.0) "1.0+100.0i" "1.+100.i")
+(test-numeric-syntax "1.0+1s2i" (make-rectangular 1.0 100.0) "1.0+100.0i" "1.+100.i")
+;; Fractional complex numbers (rectangular notation)
+(test-numeric-syntax "1/2+3/4i" (make-rectangular (/ 1 2) (/ 3 4)))
+;; Mixed fractional/decimal notation complex numbers (rectangular notation)
+(test-numeric-syntax "0.5+3/4i" (make-rectangular 0.5 (/ 3 4))
+  "0.5+0.75i" ".5+.75i" "0.5+3/4i" ".5+3/4i" "500.0e-3+750.0e-3i")
+;; Complex NaN, Inf (rectangular notation)
+;;(test-numeric-syntax "+nan.0+nan.0i" (make-rectangular the-nan the-nan) "+NaN.0+NaN.0i") 
+(test-numeric-syntax "+inf.0+inf.0i" (make-rectangular +inf.0 +inf.0) "+Inf.0+Inf.0i")
+(test-numeric-syntax "-inf.0+inf.0i" (make-rectangular -inf.0 +inf.0) "-Inf.0+Inf.0i")
+(test-numeric-syntax "-inf.0-inf.0i" (make-rectangular -inf.0 -inf.0) "-Inf.0-Inf.0i")
+(test-numeric-syntax "+inf.0-inf.0i" (make-rectangular +inf.0 -inf.0) "+Inf.0-Inf.0i")
+;; Complex numbers (polar notation)
+;; Need to account for imprecision in write output.
+;;(test-numeric-syntax "1@2" -0.416146836547142+0.909297426825682i "-0.416146836547142+0.909297426825682i")
+;; Base prefixes
+(test-numeric-syntax "#x11" 17 "17")
+(test-numeric-syntax "#X11" 17 "17")
+(test-numeric-syntax "#d11" 11 "11")
+(test-numeric-syntax "#D11" 11 "11")
+(test-numeric-syntax "#o11" 9 "9")
+(test-numeric-syntax "#O11" 9 "9")
+(test-numeric-syntax "#b11" 3 "3")
+(test-numeric-syntax "#B11" 3 "3")
+(test-numeric-syntax "#o7" 7 "7")
+(test-numeric-syntax "#xa" 10 "10")
+(test-numeric-syntax "#xA" 10 "10")
+(test-numeric-syntax "#xf" 15 "15")
+(test-numeric-syntax "#x-10" -16 "-16")
+(test-numeric-syntax "#d-10" -10 "-10")
+(test-numeric-syntax "#o-10" -8 "-8")
+(test-numeric-syntax "#b-10" -2 "-2")
+;; Combination of prefixes
+(test-numeric-syntax "#e#x10" 16 "16")
+(test-numeric-syntax "#i#x10" 16.0 "16.0" "16.")
+(test-numeric-syntax "#x#i10" 16.0 "16.0" "16.")
+(test-numeric-syntax "#i#x1/10" 0.0625 "0.0625")
+(test-numeric-syntax "#x#i1/10" 0.0625 "0.0625")
+;; (Attempted) decimal notation with base prefixes
+(test-numeric-syntax "#d1." 1.0 "1.0" "1.")
+(test-numeric-syntax "#d.1" 0.1 "0.1" ".1" "100.0e-3")
+(test-numeric-syntax "#x1e2" 482 "482")
+(test-numeric-syntax "#d1e2" 100.0 "100.0" "100.")
+;; Fractions with prefixes
+(test-numeric-syntax "#x10/2" 8 "8")
+(test-numeric-syntax "#x11/2" (/ 17 2) "17/2")
+(test-numeric-syntax "#d11/2" (/ 11 2) "11/2")
+(test-numeric-syntax "#o11/2" (/ 9 2) "9/2")
+(test-numeric-syntax "#b11/10" (/ 3 2) "3/2")
+;; Complex numbers with prefixes
+;;(test-numeric-syntax "#x10+11i" (make-rectangular 16 17) "16+17i")
+(test-numeric-syntax "#d1.0+1.0i" (make-rectangular 1.0 1.0) "1.0+1.0i" "1.+1.i")
+(test-numeric-syntax "#d10+11i" (make-rectangular 10 11) "10+11i")
+;;(test-numeric-syntax "#o10+11i" (make-rectangular 8 9) "8+9i")
+;;(test-numeric-syntax "#b10+11i" (make-rectangular 2 3) "2+3i")
+;;(test-numeric-syntax "#e1.0+1.0i" (make-rectangular 1 1) "1+1i" "1+i")
+;;(test-numeric-syntax "#i1.0+1.0i" (make-rectangular 1.0 1.0) "1.0+1.0i" "1.+1.i")
+
+(define-syntax test-precision
+  (syntax-rules ()
+    ((test-round-trip str alt ...)
+     (let* ((n (string->number str))
+            (str2 (number->string n))
+            (accepted (list str alt ...))
+            (ls (member str2 accepted)))
+       (test-assert (string-append "(member? " str2 " "
+                                   (let ((out (open-output-string)))
+                                     (write accepted out)
+                                     (get-output-string out))
+                                   ")")
+         (pair? ls))
+       (when (pair? ls)
+         (test-assert (string-append "(eqv?: " str " " str2 ")")
+           (eqv? n (string->number (car ls)))))))))
+
+(test-precision "-1.7976931348623157e+308" "-inf.0")
+(test-precision "4.940656458412465e-324" "4.94065645841247e-324" "5.0e-324" "0.0")
+(test-precision "9.881312916824931e-324" "9.88131291682493e-324" "1.0e-323" "0.0")
+(test-precision "1.48219693752374e-323" "1.5e-323" "0.0")
+(test-precision "1.976262583364986e-323" "1.97626258336499e-323" "2.0e-323" "0.0")
+(test-precision "2.470328229206233e-323" "2.47032822920623e-323" "2.5e-323" "0.0")
+(test-precision "2.420921664622108e-322" "2.42092166462211e-322" "2.4e-322" "0.0")
+(test-precision "2.420921664622108e-320" "2.42092166462211e-320" "2.421e-320" "0.0")
+(test-precision "1.4489974452386991" "1.4489975")
+(test-precision "0.14285714285714282" "0.14285714285714288" "0.14285715")
+(test-precision "1.7976931348623157e+308" "+inf.0")
+
+(test-end)
+
+(test-end)
+
+(test-begin "6.14 System interface")
+
+;; 6.14 System interface
+
+;; (test "/usr/local/bin:/usr/bin:/bin" (get-environment-variable "PATH"))
+
+(test #t (string? (get-environment-variable "PATH")))
+
+;; (test '(("USER" . "root") ("HOME" . "/")) (get-environment-variables))
+
+(let ((env (get-environment-variables)))
+  (define (env-pair? x)
+    (and (pair? x) (string? (car x)) (string? (cdr x))))
+  (define (all? pred ls)
+    (or (null? ls) (and (pred (car ls)) (all? pred (cdr ls)))))
+  (test #t (list? env))
+  (test #t (all? env-pair? env)))
+
+(test #t (list? (command-line)))
+
+(test #t (real? (current-second)))
+(test #t (inexact? (current-second)))
+(test #t (exact? (current-jiffy)))
+(test #t (exact? (jiffies-per-second)))
+
+(test #t (list? (features)))
+(test #t (and (memq 'r7rs (features)) #t))
+
+(test #t (file-exists? "."))
+(test #f (file-exists? " no such file "))
+
+(test #t (file-error?
+          (guard (exn (else exn))
+            (delete-file " no such file "))))
+
+(test-end)
+
+(test-end)