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SketchyLISP
Reference
  Copyright (C) 2006
Nils M Holm

<=

Conformance: R5RS

Purpose: Check whether two or more numbers are in non-ascending order. Return #t, if a<=b<=... and otherwise #f.

Arguments:
A - number
B... - numbers

Implementation:

(define (<= a . b)
  (letrec
    ((lteq (lambda (a b)
      (cond ((eq? a #t) #t)
        ((> a b) #t)
        (#t b)))))
    (cond ((null? b)
        (bottom '(too few arguments to <=)))
      (#t (neq? (reduce lteq (cons a b) #f)
                #t)))))

Example:

(<= 9 9 10) 
=> #t

See also:
digits, <, >, >=, n<=.