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Mirrors > Home > MPE Home > Th. List > ninba  Unicode version 
Description: Miscellaneous inference relating falsehoods. (Contributed by NM, 31Mar1994.) 
Ref  Expression 

ninba.1 
Ref  Expression 

ninba 
Step  Hyp  Ref  Expression 

1  ninba.1  . . 3  
2  1  niabn 917  . 2 
3  2  bicomd 192  1 
Colors of variables: wff set class 
Syntax hints: wn 3 wi 4 wb 176 wa 358 
This theorem was proved from axioms: ax1 5 ax2 6 ax3 7 axmp 8 
This theorem depends on definitions: dfbi 177 dfan 360 
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