t3x.org / sketchy / library / not-equalp.html
SketchyLISP
Reference
  Copyright (C) 2007
Nils M Holm

not-equal?

Conformance: SketchyLISP Extension

Purpose: Compare data with negative result.

Arguments:
A - datum
B - datum

Implementation:

(define (not-equal? a b)
  (eq? (equal? a b) #f))

Example:

(not-equal? '(a b (c d (e)) f) '(a b (c d (x)) f)) 
=> #t

See also:
equal?, neq?.