Metamath Proof Explorer


Theorem rerecid2d

Description: Multiplication of a number and its reciprocal. (Contributed by SN, 25-Nov-2025)

Ref Expression
Hypotheses sn-rereccld.a φ A
sn-rereccld.z φ A 0
Assertion rerecid2d φ 1 / A A = 1

Proof

Step Hyp Ref Expression
1 sn-rereccld.a φ A
2 sn-rereccld.z φ A 0
3 1 2 sn-rereccld φ 1 / A
4 1 2 rerecidd φ A 1 / A = 1
5 1 3 4 remulinvcom φ 1 / A A = 1