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Theorem eubidv 1951
 Description: Formula-building rule for uniqueness quantifier (deduction rule). (Contributed by NM, 9-Jul-1994.)
Hypothesis
Ref Expression
eubidv.1 (𝜑 → (𝜓𝜒))
Assertion
Ref Expression
eubidv (𝜑 → (∃!𝑥𝜓 ↔ ∃!𝑥𝜒))
Distinct variable group:   𝜑,𝑥
Allowed substitution hints:   𝜓(𝑥)   𝜒(𝑥)

Proof of Theorem eubidv
StepHypRef Expression
1 nfv 1462 . 2 𝑥𝜑
2 eubidv.1 . 2 (𝜑 → (𝜓𝜒))
31, 2eubid 1950 1 (𝜑 → (∃!𝑥𝜓 ↔ ∃!𝑥𝜒))
 Colors of variables: wff set class Syntax hints:   → wi 4   ↔ wb 103  ∃!weu 1943 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  df-nf 1391  df-eu 1946 This theorem is referenced by:  eubii  1952  eueq2dc  2775  eueq3dc  2776  reuhypd  4250  feu  5124  funfveu  5240  dff4im  5366  acexmid  5563
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