====== Equation solving ======
{{tag>math arithmetic problem_solving}}
===== Description =====
Solving equalization with constraints, which can only be above zero

**Source**:  PROLOG str. 194 Wydawnictwo PLJ Warszawa 1991 ISBN 83-85190-63-5
===== Download =====
Program source code: {{equation_solving.pl}}
===== Listing =====
<code prolog>
liczba(0).
liczba(I) :- liczba(L), I is L + 1.

plus(X, Y, Z) :- Z is X + Y.
minus(X, Y, Z) :- Z is X - Y.

rownanie(X, Y) :- liczba(X), plus(X, 3 ,8), liczba(Y), minus(X, Y, 3), !.

test :- rownanie(X, Y).</code>
===== Comments =====