Formal Proof
| Proposition | Derivation |
|---|---|
| Given | |
| Given | |
| Material implication | |
| Disjunctive syllogism |
Read more about this topic: Modus Tollens
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“It comes to pass oft that a terrible oath, with a swaggering accent sharply twanged off, gives manhood more approbation than ever proof itself would have earned him.”
—William Shakespeare (1564–1616)