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Task/Amb/Mercury/amb-1.mercury

@@ -0,0 +1,25 @@
+:- module amb.
+:- interface.
+:- import_module io.
+:- pred main(io::di, io::uo) is cc_multi.
+:- implementation.
+:- import_module list, string, char, int.
+
+main(!IO) :-
+        ( solution(S) -> io.write_string(S, !IO), io.nl(!IO)
+        ; io.write_string("No solutions found :-(\n", !IO) ).
+
+:- pred solution(string::out) is nondet.
+solution(S) :-
+        member(A, ["the", "that", "a"]),
+        member(N, ["frog", "elephant", "thing"]),
+        member(V, ["walked", "treaded", "grows"]),
+        member(E, ["slowly", "quickly"]),
+        S = join_list(" ", [A, N, V, E]),
+        rule1(A, N), rule1(N, V), rule1(V, E).
+
+:- pred rule1(string::in, string::in) is semidet.
+rule1(A, B) :- last_char(A) = C, first_char(B, C, _).
+
+:- func last_char(string::in) = (char::out) is semidet.
+last_char(S) = C :- index(S, length(S) - 1, C).

Task/Amb/Mercury/amb-2.mercury

@@ -0,0 +1,6 @@
+:- pred noun(string).
+:- mode noun(out) is multi.    % provide any one noun.
+:- mode noun(in) is semidet.   % fail if given string isn't a known noun.
+noun("frog").
+noun("elephant").
+noun("thing").