SOLUTION: phil 10 [10] Use indirect proof: / ∴ ~~{[Z v (Z ⊃ Q)] v M}

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Question 1195750: phil 10
[10] Use indirect proof:
/ ∴ ~~{[Z v (Z ⊃ Q)] v M}
Answer by mccravyedwin(406) About Me  (Show Source):
You can put this solution on YOUR website!

1. Z v ~Z                  tautology
2. Z v (~Z v Q)            1, addition
3. Z v (Z ⊃ Q)             2, material implication
4. [Z v (Z ⊃ Q)] v M       3, addition
5.  ~~{[Z v (Z ⊃ Q)] v M}  4, double negation

But that does not use indirect proof

1.                         | ~~~{[Z v (Z ⊃ Q)] v M}I    AIP
2.                         |


Edwin