RosettaCodeData/Task/Power-set/Prolog/power-set-3.pro

19 lines
431 B
Prolog

:- use_module(library(chr)).
:- chr_constraint chr_power_set/2, chr_power_set/1, clean/0.
clean @ clean \ chr_power_set(_) <=> true.
clean @ clean <=> true.
only_one @ chr_power_set(A) \ chr_power_set(A) <=> true.
creation @ chr_power_set([H | T], A) <=>
append(A, [H], B),
chr_power_set(T, A),
chr_power_set(T, B),
chr_power_set(B).
empty_element @ chr_power_set([], _) <=> chr_power_set([]).