Propositional wffs and truth tables belong to a system of
Chapter 1, Problem 53(choose chapter or problem)
Propositional wffs and truth tables belong to a system of two-valued logic because everything has one of two values, False or True. Three-valued logic allows a third value of Null or unknown (Section 5.3 discusses the implications of three-valued logic on databases). The truth tables for this three-valued system follow
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