Editing Modus ponendo tollens (section)

==Overview==
MPT is usually described as having the form:
#Not both A and B
#A
#Therefore, not B
For example:
# Ann and Bill cannot both win the race.
# Ann won the race.
# Therefore, Bill cannot have won the race.

As [[E. J. Lemmon]] describes it: "''Modus ponendo tollens'' is the principle that, if the negation of a conjunction holds and also one of its conjuncts, then the negation of its other conjunct holds."<ref>[[E. J. Lemmon|Lemmon, Edward John]]. 2001. ''Beginning Logic''. [[Taylor and Francis]]/CRC Press, p. 61.</ref>

In [[Table of logic symbols|logic notation]] this can be represented as:
# <math> \neg (A \land B)</math>
# <math> A</math>
# <math> \therefore \neg B</math>

Based on the [[Sheffer Stroke]] (alternative denial), "|", the inference can also be formalized in this way:
# <math> A\,|\,B</math>
# <math> A</math>
# <math> \therefore \neg B</math>