Unformatted text preview: Consider the following invalid argument: All actors who win academy awards are famous. Harrison Ford has never won an academy award. Harrison Ford is not famous How might we demonstrate informally that the conclusion of this argument is not a consequence of the given premises? The formal method for demonstrating logical nonconsequence is to build a counterexample world, using Tarski’s World, in which the premises of the argument are true while the conclusion is false. Consider this invalid argument expressed in the block’s language of Tarski’s World. How might we build a formal counterexample? Adjoins(a, b) SameCol(b, c) FrontOf(c, b) FrontOf(c, a) Another demonstration of nonconsequence: Exercise 2.21...
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- Spring '06
- Logic, Harrison Ford, logical consequence