Theorem 4exbidv 1805

Description: Formula-building rule for 4 existential quantifiers (deduction form). (Contributed by NM, 3-Aug-1995.)

Hypothesis

Ref	Expression
4exbidv.1	⊢ (𝜑 → (𝜓 ↔ 𝜒))

Assertion

Ref	Expression
4exbidv	⊢ (𝜑 → (∃𝑥∃𝑦∃𝑧∃𝑤𝜓 ↔ ∃𝑥∃𝑦∃𝑧∃𝑤𝜒))

Distinct variable groups:   𝜑,𝑥   𝜑,𝑦   𝜑,𝑧   𝜑,𝑤

Allowed substitution hints:   𝜓(𝑥,𝑦,𝑧,𝑤)   𝜒(𝑥,𝑦,𝑧,𝑤)

Proof of Theorem 4exbidv

Step	Hyp	Ref	Expression
1		4exbidv.1	. . 3 ⊢ (𝜑 → (𝜓 ↔ 𝜒))
2	1	2exbidv 1803	. 2 ⊢ (𝜑 → (∃𝑧∃𝑤𝜓 ↔ ∃𝑧∃𝑤𝜒))
3	2	2exbidv 1803	1 ⊢ (𝜑 → (∃𝑥∃𝑦∃𝑧∃𝑤𝜓 ↔ ∃𝑥∃𝑦∃𝑧∃𝑤𝜒))

Syntax hints:   → wi 4   ↔ wb 104  ∃wex 1433

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-5 1388  ax-gen 1390  ax-ie1 1434  ax-ie2 1435  ax-4 1452  ax-17 1471  ax-ial 1479

This theorem depends on definitions:  df-bi 116

This theorem is referenced by:  ceqsex8v  2678  copsex4g  4098  opbrop  4546  ovi3  5819  brecop  6422  th3q  6437  dfplpq2  7010  dfmpq2  7011  enq0sym  7088  enq0ref  7089  enq0tr  7090  enq0breq  7092  addnq0mo  7103  mulnq0mo  7104  addnnnq0  7105  mulnnnq0  7106  addsrmo  7386  mulsrmo  7387  addsrpr  7388  mulsrpr  7389