Demorgan's theorems are used in simplifying expressions which includes a product or sum of variables is inverted
Demorgan's First Theorem:
When the OR sum of two variables is inverted, this is equal to inverting each variable individually and then ANDing these inverted variables.
________ ____ _____
A + B = A . B
Demorgan's Second Theorem:
When the AND product of two variables is inverted, this is equal to inverting each variable individually and the ORing them.
______ ___ ___
(A . B ) = A + B
