theorem :: TWOSCOMP:26

( xor3 . <*0,0,0*> = 0 & xor3 . <*0,0,1*> = 1 & xor3 . <*0,1,0*> = 1 & xor3 . <*0,1,1*> = 0 & xor3 . <*1,0,0*> = 1 & xor3 . <*1,0,1*> = 0 & xor3 . <*1,1,0*> = 0 & xor3 . <*1,1,1*> = 1 )