Update: NAL.h: use intensional intersection which is extensional union to build an extensional set from two, not extensional intersection
@@ -115,7 +115,7 @@ ReduceTerm( (A & A), A )
ReduceTerm( (A | A), A )
ReduceStatement( (A && A), A )
//Extensional set
-ReduceTerm( ({A} & {B}), {A B} )
+ReduceTerm( ({A} | {B}), {A B} )
//Intensional set
ReduceTerm( ([A] & [B]), [A B] )
