return empty vec if lhs & rhs are already unioned
@@ -132,6 +132,9 @@ impl<L: SynthLanguage> Applier<L, SynthAnalysis> for NotUndefined<L> {
}
let id = apply_pat(self.rhs.ast.as_ref(), egraph, subst);
+ if id == matched_id {
+ return vec![];
+ }
if !egraph[id].data.is_defined() {
return vec![];
