;'<<SPEC'
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### `gt?` ###
-> Tests for functionality "Evaluate Robin Expression (with Arith)"
`gt?` evaluates both of its arguments to numbers, then evaluates to `#t`
if the first number is strictly greater than the second.
| (gt? 6 4)
= #t
| (gt? 6 8)
= #f
| (gt? 6 6)
= #f
| (gt? 1610612736 (subtract 0 1610612736)))
= #t
| (gt? (subtract 0 1610612736) 1610612736)
= #f
| (gt? 2147483646 2147483647)
= #f
| (gt? 1 2147483647)
= #f
| (gt? (subtract 0 2147483647) (subtract 0 2147483646))
= #f
| (gt? (subtract 0 2147483647) (subtract 0 1))
= #f
| (gt? 0 (subtract (subtract 0 1073741824) 1073741824)))
= #t
`gt?` expects exactly two arguments, both numbers.
| (gt? 14)
? abort (illegal-arguments
| (gt? 14 23 57)
? abort (illegal-arguments
| (gt? 14 #t)
? abort (expected-number #t)
| (gt? #t 51)
? abort (expected-number #t)
'<<SPEC'
(define gt? (fun (a b)
(bind cmp-same-sign? (fun (a b c)
(equal? (sign (subtract a b)) c))
(if (equal? (sign a) (sign b))
(cmp-same-sign? a b 1)
(cmp-same-sign? (subtract (sign a) 1) (subtract (sign b) 1) 1)))))