| Description: Multiplication is an
operation on the complex numbers. This axiom tells
us that · is defined only on complex
numbers which is analogous to
the way that other operations are defined, for example see subf 11486
or
eff 16171. However, while Metamath can handle this
axiom, if we wish to work
with weaker complex number axioms, we can avoid it by using the less
specific mulcl 11211. Note that uses of ax-mulf 11207 can be eliminated by using
the defined operation (𝑥 ∈ ℂ, 𝑦 ∈ ℂ ↦ (𝑥 · 𝑦)) in place of
·, as seen in mpomulf 11222.
This axiom is justified by Theorem axmulf 11158. (New usage is discouraged.)
(Contributed by NM, 19-Oct-2004.) |