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Theorem frege65c 44770
Description: A kind of Aristotelian inference. This judgement replaces the mode of inference barbara 2689 when the minor premise has a general context. Proposition 65 of [Frege1879] p. 53. (Contributed by RP, 24-Dec-2019.) (Proof modification is discouraged.)
Hypothesis
Ref Expression
frege59c.a 𝐴𝐵
Assertion
Ref Expression
frege65c (∀𝑥(𝜑𝜓) → (∀𝑥(𝜓𝜒) → ([𝐴 / 𝑥]𝜑[𝐴 / 𝑥]𝜒)))

Proof of Theorem frege65c
StepHypRef Expression
1 sbcim1 3795 . . 3 ([𝐴 / 𝑥](𝜑𝜓) → ([𝐴 / 𝑥]𝜑[𝐴 / 𝑥]𝜓))
2 frege59c.a . . . 4 𝐴𝐵
32frege64c 44769 . . 3 (([𝐴 / 𝑥]𝜑[𝐴 / 𝑥]𝜓) → (∀𝑥(𝜓𝜒) → ([𝐴 / 𝑥]𝜑[𝐴 / 𝑥]𝜒)))
41, 3syl 18 . 2 ([𝐴 / 𝑥](𝜑𝜓) → (∀𝑥(𝜓𝜒) → ([𝐴 / 𝑥]𝜑[𝐴 / 𝑥]𝜒)))
52frege61c 44766 . 2 (([𝐴 / 𝑥](𝜑𝜓) → (∀𝑥(𝜓𝜒) → ([𝐴 / 𝑥]𝜑[𝐴 / 𝑥]𝜒))) → (∀𝑥(𝜑𝜓) → (∀𝑥(𝜓𝜒) → ([𝐴 / 𝑥]𝜑[𝐴 / 𝑥]𝜒))))
64, 5ax-mp 5 1 (∀𝑥(𝜑𝜓) → (∀𝑥(𝜓𝜒) → ([𝐴 / 𝑥]𝜑[𝐴 / 𝑥]𝜒)))
Colors of variables:    wff setvar class
This proof depends on syntax axioms:  wi 4  wal 1568  wcel 2145  [wsbc 3742
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 2734  ax-frege1 44632  ax-frege2 44633  ax-frege8 44651  ax-frege58b 44743
This proof depends on definitions:  df-bi 210  df-an 402  df-tru 1573  df-ex 1813  df-sb 2100  df-clab 2741  df-cleq 2754  df-clel 2837  df-v 3455  df-sbc 3743
This theorem is used by:  frege66c  44771
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