Metamath Proof Explorer


Theorem 2timesi

Description: Two times a number. (Contributed by NM, 1-Aug-1999)

Ref Expression
Hypothesis 2timesi.1 A
Assertion 2timesi 2 A = A + A

Proof

Step Hyp Ref Expression
1 2timesi.1 A
2 2times A 2 A = A + A
3 1 2 ax-mp 2 A = A + A