misc.prolog


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:- module(misc, [filter/3, head/2, tail/2]).


filter(List, Predicate, Result) :-
    Test =.. [Predicate,X],
    findall(X, Test, No),
    subtract(List, No, Result).


head(X,[Y]) :- X = Y.
head(X,[Y|_]) :- X = Y.


tail(X,[]) :- X = [].
tail(X,[_]) :- X = [].
tail(X,[_|Y]) :- X = Y.