Checking if one list is begining of second
Source: PROLOG str. 51 Wydawnictwo PLJ Warszawa 1991 ISBN 83-85190-63-5
Program source code: list_prefix.pl
prefiks([], _). prefiks([X|L1], [X|L2]) :- prefiks(L1, L2). test :- prefiks([d, f, w, k], [d, f, w, k, r, u, v, z]).