diff --git a/src/ikarus.boot b/src/ikarus.boot
index 557efa5..a20f6b5 100644
Binary files a/src/ikarus.boot and b/src/ikarus.boot differ
diff --git a/src/libcompile.ss b/src/libcompile.ss
index 2593b62..dc1bddd 100644
--- a/src/libcompile.ss
+++ b/src/libcompile.ss
@@ -487,6 +487,16 @@
                  (record-case info
                    [(case-info L args proper) proper])]))]
         [else #f]))
+    (define (single-value-consumer? x)
+      (record-case x
+        [(clambda L cases F)
+         (and (fx= (length cases) 1)
+              (record-case (car cases)
+                [(clambda-case info body)
+                 (record-case info
+                   [(case-info L args proper)
+                    (and proper (fx= (length args) 1))])]))]
+        [else #f])) 
     (define (valid-mv-producer? x)
       (record-case x
         [(funcall) #t]
@@ -507,6 +517,8 @@
              (let ([producer (inline (car rand*) '())] 
                    [consumer (cadr rand*)])
                (cond
+                 [(single-value-consumer? consumer)
+                  (inline consumer (list producer))]
                  [(and (valid-mv-consumer? consumer)
                        (valid-mv-producer? producer))
                   (make-mvcall producer consumer)]
diff --git a/src/libcore.ss b/src/libcore.ss
index 4eb4b8c..829743f 100644
--- a/src/libcore.ss
+++ b/src/libcore.ss
@@ -1597,8 +1597,11 @@ reference-implementation:
          (revcons (reverse ls ls ls '())
             (append ($car ls*) ($cdr ls*)))])))
   (primitive-set! 'append
-    (lambda (ls . ls*)
-      (append ls ls*))))
+    (case-lambda
+      [() '()]
+      [(ls) ls]
+      [(ls . ls*)
+       (append ls ls*)])))
 
 
 (primitive-set! 'list->vector
diff --git a/src/makefile.ss b/src/makefile.ss
index e166454..c9b8284 100755
--- a/src/makefile.ss
+++ b/src/makefile.ss
@@ -26,6 +26,7 @@
     syntax quasisyntax unsyntax unsyntax-splicing datum
     let let* let-values cond case define-record or and when unless do
     include parameterize trace untrace trace-lambda trace-define
+    rec
     time))
 
 
diff --git a/src/psyntax-7.1.ss b/src/psyntax-7.1.ss
index 6448740..997a317 100644
--- a/src/psyntax-7.1.ss
+++ b/src/psyntax-7.1.ss
@@ -4676,3 +4676,10 @@
       [(_ expr)
        #'(time-it (lambda () expr) 'expr)])))
 
+(define-syntax rec
+  (lambda (x)
+    (syntax-case x ()
+      [(_ name proc) (identifier? #'name)
+       #'(letrec ([name proc])
+           name)])))
+