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Theorem frege63c 44925
Description: Analogue of frege63b 44907. Proposition 63 of [Frege1879] p. 52. (Contributed by RP, 24-Dec-2019.) (Proof modification is discouraged.)
Hypothesis
Ref Expression
frege59c.a 𝐴 ∈ 𝐵
Assertion
Ref Expression
frege63c ([𝐴 / 𝑥]𝜑 → (𝜓 → (∀𝑥(𝜑 → 𝜒) → [𝐴 / 𝑥]𝜒)))

Proof of Theorem frege63c
StepHypRef Expression
1 frege59c.a . . 3 𝐴 ∈ 𝐵
21frege62c 44924 . 2 ([𝐴 / 𝑥]𝜑 → (∀𝑥(𝜑 → 𝜒) → [𝐴 / 𝑥]𝜒))
3 frege24 44814 . 2 (([𝐴 / 𝑥]𝜑 → (∀𝑥(𝜑 → 𝜒) → [𝐴 / 𝑥]𝜒)) → ([𝐴 / 𝑥]𝜑 → (𝜓 → (∀𝑥(𝜑 → 𝜒) → [𝐴 / 𝑥]𝜒))))
42, 3ax-mp 5 1 ([𝐴 / 𝑥]𝜑 → (𝜓 → (∀𝑥(𝜑 → 𝜒) → [𝐴 / 𝑥]𝜒)))
Colors of variables:    wff setvar class
This proof depends on syntax axioms:   → wi 4  ∀wal 1568   ∈ wcel 2145  [wsbc 3739
This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1828  ax-4 1842  ax-5 1943  ax-6 2000  ax-7 2041  ax-8 2147  ax-9 2155  ax-ext 2733  ax-frege1 44789  ax-frege2 44790  ax-frege8 44808  ax-frege58b 44900
This proof depends on definitions:  df-bi 210  df-an 402  df-tru 1573  df-ex 1813  df-sb 2100  df-clab 2740  df-cleq 2753  df-clel 2836  df-v 3453  df-sbc 3740
This theorem is used by:  frege91  44953
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