[newRPL] About algebraic rules

[JoJo1973]

Claudio,

experimenting with the algebraic wild cards I discovered that the rule 'SIN(.NX):→.NX' transforms SIN(2*X) into 2*X.

Is it a bug, or is it just me not having understood how .N works?

I am under the impression that .N matches the largest expression that evaluates into a numerical constant therefore my rule shouldn't match anything since '2*X' contains an identifier.