(define /=
(lambda (x . y)
(not (apply = (cons (x y))))))=/ a a :: a -> a -> Bool
=/ a a = not (a = b) a, b = b, a
GHCi, version 6.8.2: http://www.haskell.org/ghc/ :? for help
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Prelude> let a ≠ b = a /= b
Prelude> :t (≠)
(≠) :: (Eq a) => a -> a -> Bool
Prelude> 1 ≠ 1
False
Prelude> 1 ≠ 2
True(define (/= a b . r)
(and (not (= a b))
(if (pair? r)
(apply /= (cons b r))
#t)))
(/= 1 1) => #f
(/= 1 2) => #t
(/= 1 2 2) => #f
(/= 1 2 3) => #t
GHCi, version 6.8.2: http://www.haskell.org/ghc/ :? for help
Loading package base ... linking ... done.
Prelude> let (≠) = (/=)
Prelude> :t (≠)
(`) :: () -> () -> Bool
Prelude> 1 ≠ 2
<interactive>:1:4:
No instance for (Num ())
arising from the literal `2' at <interactive>:1:4
Possible fix: add an instance declaration for (Num ())
In the second argument of `(`)', namely `2'
In the expression: 1 ` 2
In the definition of `it': it = 1 ` 2(define (/= a b . r) (and (not (= a b)) (or (null? r) (apply /= b r))))
GHCi, version 6.8.2: http://www.haskell.org/ghc/ :? for help
Loading package base ... linking ... done.
Prelude> 1 ≠ 2
21 i i i i i i i ooooo o ooooooo ooooo ooooo
I I I I I I I 8 8 8 8 8 o 8 8
I \ `+' / I 8 8 8 8 8 8
\ `-+-' / 8 8 8 ooooo 8oooo
`-__|__-' 8 8 8 8 8
| 8 o 8 8 o 8 8
------+------ ooooo 8oooooo ooo8ooo ooooo 8
(define (/= . terms)
(define (test ts acc)
(if (pair? ts)
(if (any (lambda (x) (eqv? x (car t))) acc)
#f
(test (cdr t) (cons (car t) acc)))
#t))
(test terms '()))(define (/= . terms)
(let test ((ts terms) (acc '()))
(or (not (pair? ts))
(and (not (any (lambda (x) (eqv? x (car ts))) acc))
(test (cdr ts) (cons (car ts) acc))))))