Metamath Proof Explorer


Theorem vtoclg1f

Description: Version of vtoclgf with one nonfreeness hypothesis replaced with a disjoint variable condition, thus avoiding dependency on ax-10 and ax-11 . (Contributed by BJ, 1-May-2019)

Ref Expression
Hypotheses vtoclg1f.nf ⊢ Ⅎ 𝑥 𝜓
vtoclg1f.maj ⊢ ( 𝑥 = 𝐴 → ( 𝜑 ↔ 𝜓 ) )
vtoclg1f.min ⊢ 𝜑
Assertion vtoclg1f ( 𝐴 ∈ 𝑉 → 𝜓 )

Proof

Step Hyp Ref Expression
1 vtoclg1f.nf ⊢ Ⅎ 𝑥 𝜓
2 vtoclg1f.maj ⊢ ( 𝑥 = 𝐴 → ( 𝜑 ↔ 𝜓 ) )
3 vtoclg1f.min ⊢ 𝜑
4 elisset ⊢ ( 𝐴 ∈ 𝑉 → ∃ 𝑥 𝑥 = 𝐴 )
5 3 2 mpbii ⊢ ( 𝑥 = 𝐴 → 𝜓 )
6 1 5 exlimi ⊢ ( ∃ 𝑥 𝑥 = 𝐴 → 𝜓 )
7 4 6 syl ⊢ ( 𝐴 ∈ 𝑉 → 𝜓 )