(define-syntax s/b
  (syntax-rules ()
    ((s/b test-expr expected-value)
     (let ((val test-expr)
           (exval expected-value)
           )
       (if (equal? val expected-value)
         (begin
           (display "s/b ")
           (display 'test-expr) 
           (display " ... ") (tc-off)
           (display val)
           (display " ... ") (tc-off)
           (display 'expected-value) (tc-off)
           (newline)
           #t)
         (begin
           (display "s/b ") 
           (display 'test-expr) 
           (display " ...")
           (newline)
           (display "...")
           (display expected-value) 
           (display "...")
           (newline)
           (display "   ")
           (display val)
           (newline)
           )
         )))))

; example:
;
; ; correct, compared to a static value
; ;> (s/b (+ 3 4) 7)
; s/b (+ 3 4) ... 7

; ; incorrect, compared to a static value
; ;> (s/b (+ 3 4) 34)
; s/b (+ 3 4) ...
; ...34...
;    12

; ; correct, compared to a dynamic value
; ;> (s/b (* 7 6) (* 6 7))
; s/b (* 7 6) ... 42 ... (* 6 7)