Assignment and valuation Definition(Valuation A truth valuation v is a function that assigns to each proposition a a unique truth value v(a) so that its value on a compund proposition is determined in accordance with the appropriate truth tables Specially, v(a) determines one possible truth assignment if a is a propositional letterAssignment and Valuation . Definition (Valuation) . . A truth valuation V is a function that assigns to each proposition α a unique truth value V(α) so that its value on a compund proposition is determined in accordance with the appropriate truth tables. Specially, V(α) determines one possible truth assignment if α is a propositional letter. Yi Li (Fudan University) Discrete Mathematics April 2, 2013 6 / 20