Users' Mathboxes Mathbox for Scott Fenton < Previous   Next >
Nearby theorems
Mirrors  >  Home  >  MPE Home  >  Th. List  >   Mathboxes  >  hbntg Structured version   Visualization version   GIF version

Theorem hbntg 36659
Description: A more general form of hbnt 2327. (Contributed by Scott Fenton, 13-Dec-2010.)
Assertion
Ref Expression
hbntg (∀𝑥(𝜑 → ∀𝑥𝜓) → (¬ 𝜓 → ∀𝑥 ¬ 𝜑))

Proof of Theorem hbntg
StepHypRef Expression
1 axc7 2347 . . 3 (¬ ∀𝑥 ¬ ∀𝑥𝜓 → 𝜓)
21con1i 148 . 2 (¬ 𝜓 → ∀𝑥 ¬ ∀𝑥𝜓)
3 con3 154 . . 3 ((𝜑 → ∀𝑥𝜓) → (¬ ∀𝑥𝜓 → ¬ 𝜑))
43al2imi 1847 . 2 (∀𝑥(𝜑 → ∀𝑥𝜓) → (∀𝑥 ¬ ∀𝑥𝜓 → ∀𝑥 ¬ 𝜑))
52, 4syl5 35 1 (∀𝑥(𝜑 → ∀𝑥𝜓) → (¬ 𝜓 → ∀𝑥 ¬ 𝜑))
Colors of variables:    wff setvar class
This proof depends on syntax axioms:  ¬ wn 3   → wi 4  ∀wal 1567
This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1827  ax-4 1841  ax-5 1942  ax-6 1999  ax-7 2040  ax-10 2177  ax-12 2212
This proof depends on definitions:  df-bi 210  df-ex 1812
This theorem is used by:  hbimtg  36660  hbng  36662
  Copyright terms: Public domain W3C validator