NFE Home New Foundations Explorer < Previous   Next >
Nearby theorems
Mirrors  >  Home  >  NFE Home  >  Th. List  >  albidh GIF version

Theorem albidh 1590
Description: Formula-building rule for universal quantifier (deduction rule). (Contributed by NM, 5-Aug-1993.)
Hypotheses
Ref Expression
albidh.1 ⊢ (φ → ∀xφ)
albidh.2 ⊢ (φ → (ψ ↔ χ))
Assertion
Ref Expression
albidh ⊢ (φ → (∀xψ ↔ ∀xχ))

Proof of Theorem albidh
StepHypRef Expression
1 albidh.1 . . 3 ⊢ (φ → ∀xφ)
2 albidh.2 . . 3 ⊢ (φ → (ψ ↔ χ))
31, 2alrimih 1565 . 2 ⊢ (φ → ∀x(ψ ↔ χ))
4 albi 1564 . 2 ⊢ (∀x(ψ ↔ χ) → (∀xψ ↔ ∀xχ))
53, 4syl 15 1 ⊢ (φ → (∀xψ ↔ ∀xχ))
Colors of variables:    wff setvar class
This proof depends on syntax axioms:   → wi 4   ↔ wb 176  ∀wal 1540
This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1546  ax-5 1557
This proof depends on definitions:  df-bi 177
This theorem is used by:  albidv  1625  albid  1772  ax10lem4  1941  ax9  1949  dral2  1966  dral2-o  2181  ax11indalem  2197  ax11inda2ALT  2198  ax11inda  2200
  Copyright terms: Public domain W3C validator