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Is this a VALID ARGUMENT?. Place truth values under the conclusion. T. T. false. If there is a row T T F it must be one of the first two rows. The conclusion is false only if p is true. T. T. T. T. false. Now place truth values under the second premise. F. F. true.
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T T false If there is a row T T F it must be one of the first two rows The conclusion is false only if p is true
T T T T false Now place truth values under the second premise.
F F true If there is a row T T F then it must be the second row When the conclusion is false the second premise is true only if r is false T T T T false
false F In this case, we won’t find it because under these conditions the first premise is false T F F true T F T false We have eliminated all but one row in our search for the possibility T T F
T F false F true T F F T false VALID There are NO conditions under which the conclusion is false when the premises are true. If the premises are true then you must accept the conclusion.
F T T F F T false F T The conclusion is false only when r is trueand q is false
F T T F F T false F T Assign values to premise #1
F T T F F T false F T Assign values to premise #1
T F true T T T T F F T false F T When the conclusion is false, the first premise is true only when p is true
T F true T T false T T F F T F false VALID F T There are no conditions under which the conclusion is false and the premises are true.
F F F F false F F The conclusion is false only if r is false
F F F F false F F Place truth values under premise #1
F F F F false F F When the conclusion is false premise #1 is true only when p is false
F F true F F F F false F F F F When the conclusion is false premise #1 is true only when p is false
F F true F F F F false F F F F If there is a row T T F then it is one of the yellow rows - complete them
F F true F T F true F F false F F T F F If there is a row T T F then it is one of the yellow rows - complete them
F F true F T F true F F false F F T invalid F F There are conditions under which the premises are true but the conclusion is false.
F F The conclusion is FALSE only if r is F F false
T Under these conditions, this premise is TRUE only if p is T T F true F F false
T T Under these conditions, this premise is TRUE only if qT true T T F true F F false
T T true F T T F true Under these conditions, this premise is TRUE only if s is F F F true F false
F T T true F T Under these conditions, this premise is FALSE T F true F F true F false
F T T It is not possible for all of the premises to be true when the conclusion is false. This is a valid argument. true F T false T F true F F true F false