| antecedent | See conditional claim.
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| chain argument | An argument consisting of three conditional claims, in which the antecedents of one premise and the conclusion are the same; the consequents of the other premise and the conclusion are the same; and the consequent of the first premise and the antecedent of the second premise are the same.
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| claim variable | A letter that stands for a claim.
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| conditional claim | A claim that state-of-affairs A cannot hold without state-of-affairs B holding as well—e.g., "If A then B." The A-part of the claim is called the antecedent; the B-part is called the consequent.
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| conditional proof | A deduction for a conditional claim "If P then Q" that proceeds by assuming that P is true and then proving that, on that assumption, Q must also be true.
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| conjunction | A compound claim made from two simpler claims. A conjunction is true if and only if both of the simpler claims that compose it are true.
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| consequent | See conditional claim.
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| deduction (proof) | A numbered sequence of truth-functional symbolizations, each member of which validly follows from earlier members by one of the truth-functional rules.
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| disjunction | A compound claim made up of two simpler claims. A disjunction is false only if both of the simpler claims that make it up are false.
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| modus ponens | An argument consisting of a conditional claim as one premise, a claim that affirms the antecedent of the conditional as a second premise, and a claim that affirms the consequent of the conditional as the conclusion.
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| negation | The contradictory of a particular claim.
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| truth-functional equivalence | Two claims are truth-functionally equivalent if and only if they have exactly the same truth table.
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| truth-functional logic | A system of logic that specifies the logical relationships among truth-functional claims—claims whose truth values depend solely upon the truth values of their simplest component parts. In particular, truth-functional logic deals with the logical functions of the terms "not," "and," "or," "if . . . then," and so on.
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| truth table | A table that lists all possible combinations of truth values for the claim variables in a symbolized claim or argument and then specifies the truth value of the claim or claims for each of those possible combinations.
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