Relation To modus Ponens
Every use of modus tollens can be converted to a use of modus ponens and one use of transposition to the premise which is a material implication. For example:
- If P, then Q. (premise -- material implication)
- If Q is false, then P is false. (derived by transposition)
- Q is false. (premise)
- Therefore, P is false. (derived by modus ponens)
Likewise, every use of modus ponens can be converted to a use of modus tollens and transposition.
Read more about this topic: Modus Tollens
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