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Theorem necon1ad 2583
Description: Contrapositive deduction for inequality. (Contributed by NM, 2-Apr-2007.)
Hypothesis
Ref Expression
necon1ad.1
Assertion
Ref Expression
necon1ad

Proof of Theorem necon1ad
StepHypRef Expression
1 df-ne 2518 . 2
2 necon1ad.1 . . 3
32con1d 116 . 2
41, 3syl5bi 208 1
Colors of variables: wff setvar class
Syntax hints:   wn 3   wi 4   wceq 1642   wne 2516
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-3 7  ax-mp 8
This theorem depends on definitions:  df-bi 177  df-ne 2518
This theorem is referenced by:  nchoicelem15  6303
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