Add #t/#f return value for apropos

scheme-core/system.scm

@@ -1126,6 +1126,8 @@
               string<? symbol->string))))
 
 (define (apropos . args)
+  (let ((syms (apply apropos-list args)))
+    (and (not (null? syms))
          (for-each (λ (sym)
                      (displayln
                       (string-append
@@ -1133,7 +1135,8 @@
                          (if (procedure? val) "procedure" "variable "))
                        "  "
                        (symbol->string sym))))
-            (apply apropos-list args)))
+                   syms)
+         #t)))
 
 (define-macro (help . args)
   `(apply help* ',args))