Metamath Proof Explorer


Theorem oppfrcllem

Description: Lemma for oppfrcl . (Contributed by Zhi Wang, 14-Nov-2025)

Ref Expression
Hypotheses oppfrcl.1
|- ( ph -> G e. R )
oppfrcl.2
|- Rel R
Assertion oppfrcllem
|- ( ph -> G =/= (/) )

Proof

Step Hyp Ref Expression
1 oppfrcl.1
 |-  ( ph -> G e. R )
2 oppfrcl.2
 |-  Rel R
3 0nelrel0
 |-  ( Rel R -> -. (/) e. R )
4 2 3 ax-mp
 |-  -. (/) e. R
5 nelne2
 |-  ( ( G e. R /\ -. (/) e. R ) -> G =/= (/) )
6 1 4 5 sylancl
 |-  ( ph -> G =/= (/) )