Metamath Proof Explorer


Theorem mulid1i

Description: Identity law for multiplication. (Contributed by NM, 14-Feb-1995)

Ref Expression
Hypothesis axi.1 A
Assertion mulid1i A 1 = A

Proof

Step Hyp Ref Expression
1 axi.1 A
2 mulid1 A A 1 = A
3 1 2 ax-mp A 1 = A