Checks for the valid application of Disjunctive Syllogism.
E.g.: (1) p V q; (2) ~p; (3) q;
We first identify which of the cited lines is the disjunction by checking
which one is longer, since the disjunction must be longer than the
negation. (Proof: The disjuntion contains the same main argument as the
negation, minus the ~ symbol, plus V and another formula.)
Once we have done this, we simply identify whether one of operands
of the disjunction is the negation of the other cited line, and the
other operand is equal to the target proposition.
Checks for the valid application of
Disjunctive Syllogism.E.g.: (1) p V q; (2) ~p; (3) q;
We first identify which of the cited lines is the disjunction by checking which one is longer, since the disjunction must be longer than the negation. (Proof: The disjuntion contains the same main argument as the negation, minus the
~symbol, plusVand another formula.) Once we have done this, we simply identify whether one of operands of the disjunction is the negation of the other cited line, and the other operand is equal to thetargetproposition.