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Theorem bj-biorfi 32795
Description: This should be labeled "biorfi" while the current biorfi 421 should be labeled "biorfri". The dual of biorf 419 is not biantr 1010 but iba 525 (and ibar 526). So there should also be a "biorfr". (Note that these four statements can actually be strengthened to biconditionals.) (Contributed by BJ, 26-Oct-2019.) (Proof modification is discouraged.)
Hypothesis
Ref Expression
bj-biorfi.1 ¬ 𝜑
Assertion
Ref Expression
bj-biorfi (𝜓 ↔ (𝜑𝜓))

Proof of Theorem bj-biorfi
StepHypRef Expression
1 bj-biorfi.1 . 2 ¬ 𝜑
2 biorf 419 . 2 𝜑 → (𝜓 ↔ (𝜑𝜓)))
31, 2ax-mp 5 1 (𝜓 ↔ (𝜑𝜓))
Colors of variables: wff setvar class
Syntax hints:  ¬ wn 3  wb 196  wo 382
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8
This theorem depends on definitions:  df-bi 197  df-or 384
This theorem is referenced by:  bj-falor  32796
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