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Theorem mt4 129
Description: The rule of modus tollens. (Contributed by Wolf Lammen, 12-May-2013.)
Hypotheses
Ref Expression
mt4.1
mt4.2
Assertion
Ref Expression
mt4

Proof of Theorem mt4
StepHypRef Expression
1 mt4.1 . 2
2 mt4.2 . . 3
32con4i 122 . 2
41, 3ax-mp 5 1
Colors of variables: wff setvar class
Syntax hints:   wn 3   wi 4
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8
This theorem is referenced by: (None)
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