ILE Home Intuitionistic Logic Explorer < Previous   Next >
Nearby theorems
Mirrors  >  Home  >  ILE Home  >  Th. List  >  cbv3h GIF version

Theorem cbv3h 1678
Description: Rule used to change bound variables, using implicit substitution. (Contributed by NM, 5-Aug-1993.) (Proof shortened by Andrew Salmon, 25-May-2011.) (Proof shortened by Wolf Lammen, 12-May-2018.)
Hypotheses
Ref Expression
cbv3h.1 (𝜑 → ∀𝑦𝜑)
cbv3h.2 (𝜓 → ∀𝑥𝜓)
cbv3h.3 (𝑥 = 𝑦 → (𝜑𝜓))
Assertion
Ref Expression
cbv3h (∀𝑥𝜑 → ∀𝑦𝜓)

Proof of Theorem cbv3h
StepHypRef Expression
1 cbv3h.1 . . 3 (𝜑 → ∀𝑦𝜑)
21nfi 1396 . 2 𝑦𝜑
3 cbv3h.2 . . 3 (𝜓 → ∀𝑥𝜓)
43nfi 1396 . 2 𝑥𝜓
5 cbv3h.3 . 2 (𝑥 = 𝑦 → (𝜑𝜓))
62, 4, 5cbv3 1677 1 (∀𝑥𝜑 → ∀𝑦𝜓)
Colors of variables: wff set class
Syntax hints:  wi 4  wal 1287
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 1381  ax-7 1382  ax-gen 1383  ax-ie1 1427  ax-ie2 1428  ax-4 1445  ax-i9 1468  ax-ial 1472
This theorem depends on definitions:  df-bi 115  df-nf 1395
This theorem is referenced by:  cbvalh  1683  ax16  1741  ax16i  1786  cleqh  2187
  Copyright terms: Public domain W3C validator