Theorem ceqsexgv 1412

Description: Elimination of an existential quantifier, using implicit substitution.

Hypothesis

Ref	Expression
ceqsexgv.1	⊢ (x = A → (φ ↔ ψ))

Assertion

Ref	Expression
ceqsexgv	⊢ (A ∈ B → (∃x(x = A ∧ φ) ↔ ψ))

Distinct variable group(s):   x,A   ψ,x

Proof of Theorem ceqsexgv

Step	Hyp	Ref	Expression
1		ax-17 925	. 2 ⊢ (ψ → ∀xψ)
2		ceqsexgv.1	. 2 ⊢ (x = A → (φ ↔ ψ))
3	1, 2	ceqsexg 1411	1 ⊢ (A ∈ B → (∃x(x = A ∧ φ) ↔ ψ))

Syntax hints:   → wi 2   ↔ wb 127   ∧ wa 196  ∃wex 678   = wceq 1091   ∈ wcel 1092

This theorem is referenced by:  ceqsrexv 1413  imasn 2616  elxp5 2641  fvopabn 2873  xpsnen 3339

This theorem was proved from axioms:  ax-1 3  ax-2 4  ax-3 5  ax-mp 6  ax-4 673  ax-5 674  ax-6 675  ax-7 676  ax-gen 677  ax-8 798  ax-9 799  ax-10 800  ax-11 801  ax-12 802  ax-16 922  ax-17 925  ax-ext 1074

This theorem depends on definitions:  df-bi 128  df-an 198  df-ex 679  df-sb 853  df-clab 1093  df-cleq 1097  df-clel 1099  df-v 1349

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