[filmor]

If the expression is supposed to be the definition and not just a derived equality, at least Mathematicians (and some Physicists) would use := instead, just as Niklaus Wirth tried to establish with Pascal.

[dhimes]

or ≡

[Nullabillity]

I've only seen that used for congruence (x ≡ y <=> f(x) = f(y), for some context-dependent f).

[dhimes]

It used to mean "define" in ancient times.