In propositional logic
we say that two binary operations
g are duals
of one another if
φ is a propositional formula,
φd, the dual of
φ, is the result of
replacing all occurrences of
f and vice versa, and each
occurrence of a binary connective with its dual.
Fitting, Melvin. First-Order Logic and Automated Theorem Proving. Springer, 1990.
Copyright © 2014 Barry Watson. All rights reserved.