Proof: Rules of Inference
Using Hypothetical and Disjunctive Syllogisms

A second group consists of the hypothetical and disjunctive syllogisms that we studied earlier:

Disjunctive Syllogism (DS)
Hypothetical Syllogism (HS)
p v q
p v q
p q
~ p
or
~ q
q r
___
q
___
p
___
pr

Modus ponens (MP)
Modus tollens (MT)
p q
p q
p
~ q
___
q
___
~ p

Disjunction and conjunction |
Hypothetical and disjunctive syllogisms | Dilemmas
Constructing a Proof

Proof

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