blob: cfdce61fcff67d4c726f8bd4d22f2386fbfa9edb (
about) (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
|
(import (algebraic-structures semigroup)
(algebraic-structures monoid)
(algebraic-structures group)
(algebraic-structures monoid fold)
(algebraic-structures list foldable))
(module (mod7 semigroup) = (algebraic-structures semigroup)
(import scheme
(chicken module)
(chicken base))
(export <>)
(define (<> x y)
(assert (integer? x))
(assert (integer? y))
(assert (not (zero? x)))
(assert (not (zero? y)))
(modulo (* x y) 7)))
(module (mod7 monoid) = (algebraic-structures monoid)
(import scheme
(chicken module)
(chicken base))
(reexport (mod7 semigroup))
(export unit)
(define unit 1))
(module (mod7 group) = (algebraic-structures group)
(import scheme
(chicken base)
(chicken module)
matchable)
(reexport (mod7 monoid))
(export inv)
(define (inv n)
(assert (integer? n))
(assert (not (zero? n)))
(match (modulo n 7)
(1 1)
(2 4)
(3 5)
(4 2)
(5 3)
(6 6))))
(module (mod7 fold) = ((algebraic-structures monoid fold) (mod7 monoid) (algebraic-structures list foldable)))
(import (prefix (mod7 group) mod7:)
(prefix (mod7 fold) mod7:))
|
