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Theorem ibibr 244
Description: Implication in terms of implication and biconditional. (Contributed by NM, 29-Apr-2005.) (Proof shortened by Wolf Lammen, 21-Dec-2013.)
Assertion
Ref Expression
ibibr ((𝜑𝜓) ↔ (𝜑 → (𝜓𝜑)))

Proof of Theorem ibibr
StepHypRef Expression
1 pm5.501 242 . . 3 (𝜑 → (𝜓 ↔ (𝜑𝜓)))
2 bicom 138 . . 3 ((𝜑𝜓) ↔ (𝜓𝜑))
31, 2syl6bb 194 . 2 (𝜑 → (𝜓 ↔ (𝜓𝜑)))
43pm5.74i 178 1 ((𝜑𝜓) ↔ (𝜑 → (𝜓𝜑)))
Colors of variables: wff set class
Syntax hints:  wi 4  wb 103
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 104  ax-ia2 105  ax-ia3 106
This theorem depends on definitions:  df-bi 115
This theorem is referenced by:  tbt  245  oibabs  834  rabxfrd  4227
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