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Theorem 3exbidv 1791
Description: Formula-building rule for 3 existential quantifiers (deduction rule). (Contributed by NM, 1-May-1995.)
Hypothesis
Ref Expression
3exbidv.1 (𝜑 → (𝜓𝜒))
Assertion
Ref Expression
3exbidv (𝜑 → (∃𝑥𝑦𝑧𝜓 ↔ ∃𝑥𝑦𝑧𝜒))
Distinct variable groups:   𝜑,𝑥   𝜑,𝑦   𝜑,𝑧
Allowed substitution hints:   𝜓(𝑥,𝑦,𝑧)   𝜒(𝑥,𝑦,𝑧)

Proof of Theorem 3exbidv
StepHypRef Expression
1 3exbidv.1 . . 3 (𝜑 → (𝜓𝜒))
21exbidv 1747 . 2 (𝜑 → (∃𝑧𝜓 ↔ ∃𝑧𝜒))
322exbidv 1790 1 (𝜑 → (∃𝑥𝑦𝑧𝜓 ↔ ∃𝑥𝑦𝑧𝜒))
Colors of variables: wff set class
Syntax hints:  wi 4  wb 103  wex 1422
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 104  ax-ia2 105  ax-ia3 106  ax-5 1377  ax-gen 1379  ax-ie1 1423  ax-ie2 1424  ax-4 1441  ax-17 1460  ax-ial 1468
This theorem depends on definitions:  df-bi 115
This theorem is referenced by:  ceqsex6v  2644  euotd  4017  oprabid  5568  eloprabga  5622  eloprabi  5853
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