Metamath Proof Explorer


Theorem recsne0

Description: If a surreal has a reciprocal, then it is non-zero. (Contributed by Scott Fenton, 5-Sep-2025)

Ref Expression
Hypotheses recsne0.1
|- ( ph -> A e. No )
recsne0.2
|- ( ph -> E. x e. No ( A x.s x ) = 1s )
Assertion recsne0
|- ( ph -> A =/= 0s )

Proof

Step Hyp Ref Expression
1 recsne0.1
 |-  ( ph -> A e. No )
2 recsne0.2
 |-  ( ph -> E. x e. No ( A x.s x ) = 1s )
3 oveq2
 |-  ( x = y -> ( A x.s x ) = ( A x.s y ) )
4 3 eqeq1d
 |-  ( x = y -> ( ( A x.s x ) = 1s <-> ( A x.s y ) = 1s ) )
5 4 cbvrexvw
 |-  ( E. x e. No ( A x.s x ) = 1s <-> E. y e. No ( A x.s y ) = 1s )
6 2 5 sylib
 |-  ( ph -> E. y e. No ( A x.s y ) = 1s )
7 simprr
 |-  ( ( ph /\ ( y e. No /\ ( A x.s y ) = 1s ) ) -> ( A x.s y ) = 1s )
8 1sne0s
 |-  1s =/= 0s
9 8 a1i
 |-  ( ( ph /\ ( y e. No /\ ( A x.s y ) = 1s ) ) -> 1s =/= 0s )
10 7 9 eqnetrd
 |-  ( ( ph /\ ( y e. No /\ ( A x.s y ) = 1s ) ) -> ( A x.s y ) =/= 0s )
11 1 adantr
 |-  ( ( ph /\ ( y e. No /\ ( A x.s y ) = 1s ) ) -> A e. No )
12 simprl
 |-  ( ( ph /\ ( y e. No /\ ( A x.s y ) = 1s ) ) -> y e. No )
13 11 12 mulsne0bd
 |-  ( ( ph /\ ( y e. No /\ ( A x.s y ) = 1s ) ) -> ( ( A x.s y ) =/= 0s <-> ( A =/= 0s /\ y =/= 0s ) ) )
14 10 13 mpbid
 |-  ( ( ph /\ ( y e. No /\ ( A x.s y ) = 1s ) ) -> ( A =/= 0s /\ y =/= 0s ) )
15 14 simpld
 |-  ( ( ph /\ ( y e. No /\ ( A x.s y ) = 1s ) ) -> A =/= 0s )
16 6 15 rexlimddv
 |-  ( ph -> A =/= 0s )