propositional theorems
- by gcc
wang's theorem to prove theorems in propositonal calculus
Label Sequent Comment
S1: P ? Q, Q ? R, ¬R ? ¬P Initial sequent.
S2: ¬P ? Q, ¬Q ? R, ¬R ? ¬P Two applications of R5.
S3: ¬P ? Q, ¬Q ? R ? ¬P, R Rl.
S4: ¬P, ¬Q ? R ? ¬P, R S4 and S5 are obtained from S3 with
R3. Note…