# Symbolic simplificaction without commutativity

I would like to expand the expression:

$$(a_x p_x + a_y p_y + a_z p_z + b m)^2$$

where:

$a_x a_y \neq a_y a_z$

Or generally speaking the objects $a_x,a_y,a_z,b$ are non-commutative for multiplication.