So, I've been playing around with Mathematica lately, and I found an interesting (what I presume to be an) error. Trying to simplify
(PlusMinus[a])^2 does not give a result of
a^2. However, it is a fact that $(\pm a)^2 == a^2$.
Obviously, this is fairly easy to work around, but it does require splitting your work up into two (or more, depending on how many times you use
PlusMinus) separate pieces.
So, am I missing something, or is this an error on Mathematica's part?