Example of list processing

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Example of list processing

member( X, [X|Tail] ).

member( X, [Head|Tail] ) :-
    member( X, Tail ).

Read this as:

X is a member of any list whose
first element is X.

X is a member of any list if
    X is a member of the tail of
    the list.

Standard terminology in list processing: The head of a list is its first element. The tail of a list is the sublist formed by its second, third, ... elements.

Jocelyn Ireson-Ireson-Paine
Mon Jul 17 22:27:41 BST 1995