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Theorem mtbii 293
Description: An inference from a biconditional, similar to modus tollens. (Contributed by NM, 27-Nov-1995.)
Hypotheses
Ref Expression
mtbii.min
mtbii.maj
Assertion
Ref Expression
mtbii

Proof of Theorem mtbii
StepHypRef Expression
1 mtbii.min . 2
2 mtbii.maj . . 3
32biimprd 214 . 2
41, 3mtoi 169 1
Colors of variables: wff setvar class
Syntax hints:   wn 3   wi 4   wb 176
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 177
This theorem is referenced by:  ax9  1949
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