Incomplete Simplification (Factoring) and Equality Check

[jclapis]

The version I use: AngouriMath v1.3.0 from NuGet

Unexpected behaviour or bug: I have the following expression:

Entity expr = "a*c + a*d + b*c + b*d";

When I call Simplify() on it, it becomes the following:

a * (c + d) + b * c + b * d

I would expect it to be the reduced form ((a + b) * (c + d)). Normally this wouldn't be a problem, but testing for equality between these two fails unless they are both in their maximally expanded forms:

Entity expr = "a*c + a*d + b*c + b*d";
Entity expr2 = "(a + b) * (c + d)";
Entity eq = new Entity.Equalsf(expr, expr2);
eq = eq.Simplify();
Console.WriteLine(eq); // Prints "a * (c + d) + b * c + b * d = (a + b) * (c + d)"

expr2 = expr2.Expand();
eq = new Entity.Equalsf(expr, expr2);
eq = eq.Simplify();
Console.WriteLine(eq); // Prints "true"

We require this equality check to function properly, and (hopefully) fixing this simplification bug will make that work.