10/3/08 10 Software under construction.
a) P⊃ Q, R⊃ Q ∴ (P∨ R)⊃ Q
b) P⊃ (Q∧R), ¬R ∴ ¬P
c) ∴ ((P⊃ Q)⊃ Q)⊃ Q
d) ∴ ((P⊃ Q)∧ (¬P⊃ Q))⊃ ¬P
12/31/09 10 Software under construction.
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