PHL 110 Study Guide - Final Guide: Omnipotence, Universal Quantification, Existential Clause
1 Feb 2015
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Contents: predicate logic derivations, universal out, existential in, existential out, universal derivation, negation rules, multiple quantifiers, relational quantification, strategies and steps, desperate measures revisited, review problems. In this unit, we use the method of derivations, like in unit 2, as a means to demonstrate that arguments in predicate logic are valid. This method is particularly important for predicate logic, because, unlike sentential logic, there is no alternative method such as truth tables to use to show that an argument is valid. The basic idea of a derivation in predicate logic is the same as for sentential logic. Moreover, all the rules of derivation you learned for sentential logic (&o, &i, o, i, o, i, O, dn, etc. ) carry over to predicate logic. The only difference is that, although in stating the rules, we use single letters to represent places where we can plug in formulas, the formulas themselves will never consist of single letters.
