Metamath Proof Explorer


Theorem rerecid2

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

Ref Expression
Hypotheses sn-rereccld.a
|- ( ph -> A e. RR )
sn-rereccld.z
|- ( ph -> A =/= 0 )
Assertion rerecid2
|- ( ph -> ( ( 1 /R A ) x. A ) = 1 )

Proof

Step Hyp Ref Expression
1 sn-rereccld.a
 |-  ( ph -> A e. RR )
2 sn-rereccld.z
 |-  ( ph -> A =/= 0 )
3 1 2 sn-rereccld
 |-  ( ph -> ( 1 /R A ) e. RR )
4 1 2 rerecid
 |-  ( ph -> ( A x. ( 1 /R A ) ) = 1 )
5 1 3 4 remulinvcom
 |-  ( ph -> ( ( 1 /R A ) x. A ) = 1 )