In this decimal digit context it would be appropriate to define
NOT d = 9 - d
Similar to NOT b = 1 - b
for binary digits. And in fuzzy logic.Taking the logic identity
a XOR b = ( a AND NOT b ) OR ( NOT a AND b )
it would be MAX( MIN( a, NOT( b ) ), MIN( NOT( a ), b ) )
Bit-wise arithmetic is great because it's operations are compatible with propositional calculus,- but I cannot see how you can do anything productive with min/max-wise defined AND/OR for base10. For example how to do you determine 324 XOR 310 in your notation?