| 1. ~C É (A É
C) 2. ~C // ~A 3. A É C 1,2 MP |
line one says: if ~C is true then the consequent is true (the statement in parentheses) Since line two is an affirmation of ~C, I know I can do MP and derive the consequent.because there is no longer anything outside the parentheses they drop away.I add my justification. Click here to go on. |