HomeHome Metamath Proof Explorer < Previous   Next >
Related theorems
GIF version

Theorem pm5.32rd 492
Description: Distribution of implication over biconditional (deduction rule).
Hypothesis
Ref Expression
pm5.32d.1 (φ → (ψ → (χθ)))
Assertion
Ref Expression
pm5.32rd (φ → ((χψ) ↔ (θψ)))

Proof of Theorem pm5.32rd
StepHypRef Expression
1 pm5.32d.1 . . 3 (φ → (ψ → (χθ)))
21pm5.32d 491 . 2 (φ → ((ψχ) ↔ (ψθ)))
3 ancom 333 . 2 ((χψ) ↔ (ψχ))
4 ancom 333 . 2 ((θψ) ↔ (ψθ))
52, 3, 43bitr4g 428 1 (φ → ((χψ) ↔ (θψ)))
Colors of variables: wff set class
Syntax hints:   → wi 2   ↔ wb 127   ∧ wa 196
This theorem was proved from axioms:  ax-1 3  ax-2 4  ax-3 5  ax-mp 6
This theorem depends on definitions:  df-bi 128  df-an 198
metamath.org