diff --git a/polimani.pl b/polimani.pl
index cce9b39..bca9745 100644
--- a/polimani.pl
+++ b/polimani.pl
@@ -38,12 +38,10 @@ polynomial_variable(X) :-
 %  Returns true if X is a power term, false otherwise.
 %  Fully reversible.
 %
-power(P) :-
-    %% Makes this more reversible
-    P = X ^ N,
+power(P^N) :-
     %% CPL(FD) library predicate to perform integer comparassions in a reversible way
     %% If 0 > N succeds, fail, otherwise check if X is a valid variable
-    (zcompare((>), 0, N); polynomial_variable(X)), fail.
+    (zcompare((<), 0, N), polynomial_variable(P)); fail.
     %% if(zcompare((>), 0, N),
     %%    fail,
     %%    polynomial_variable(X)