[aratakareigen]

It is a convention, not a rule, in mathematics to use (+) to represent operations that are commutative (i.e. abelian) groups.

But this convention is not at all respected in programming (e.g. + for string concatenation in many languages) so I have to admit that it's pretty irrelevant.

[NoodleIncident]

The war to keep programming operators at all consistent with mathematics was lost long ago, with `=` and `==` being the worst offenders.

[nemetroid]

To be fair, mathematics uses = to indicate assignment as well, e.g. for summation limits.