How to make logical OR with AND,and NOT?

问题

How to create a logical OR with logical AND, and logical NOT?

回答1:

Check De Morgans's laws. You are looking for the Substitution form.

P OR Q = NOT( (NOT P) AND (NOT Q) )

回答2:

It's De Morgan's Law:

A OR B = NOT ( NOT A AND NOT B )

Truth table for A OR B:

A B  X
0 0  0
0 1  1
1 0  1
1 1  1

Truth table for the De Morgan equivalent:

A B  !A  !B  (!A AND !B)   !(!A AND !B)
0 0   1   1       1              0
0 1   1   0       0              1
1 0   0   1       0              1
1 1   0   0       0              1

回答3:

Like not (not x and not y) ?

回答4:

Pretty simple:

A || B = !(!A && !B)

回答5:

Using DeMorgans law. The Negation of (Not A "And" Not B)

来源：https://stackoverflow.com/questions/8374895/how-to-make-logical-or-with-and-and-not