Need urgent help in Prolog !!

Hello,

I am a student at the Paris-Sud University near Paris.

I am looking for a source code in Prolog concerning the pitch problem.

Let me explain it :

I have two pitches (one of 7 liters and one of 5 liters). I must

program the case in order to get one pitch with 4 liters. It is

easy to solve it by hand but not really in Prolog.

I have only three possible operations :

- fill one of them completely

- empty one completely

- fill one with the content of the other

I must not use the following : CUT, FAIL and NOT

The main predicate must be "solution(X)" where X is a list of

[OPERATION, STATE] couple :

STATE represents the state of one pitch

OPERATION is an operation that takes to the previous state.

I am looking for such a source code.

I do not know where to find it.

If you could help me, that would be nice.

Yours faithfully,

Antoine Vignau