Metamath Proof Explorer


Theorem recid2

Description: Multiplication of a number and its reciprocal. (Contributed by NM, 22-Jun-2006) (Proof shortened by Mario Carneiro, 27-May-2016)

Ref Expression
Assertion recid2 A A 0 1 A A = 1

Proof

Step Hyp Ref Expression
1 ax-1cn 1
2 divcan1 1 A A 0 1 A A = 1
3 1 2 mp3an1 A A 0 1 A A = 1