Glossary

addition: A ⊢ A ∨ B
conditional contraction: A → (A → B) ⊢ A → B
conditional identity: B ⊢ A → A
DeMorgan laws: . . .
disjunctive syllogism: A ∨ B, ¬B ⊢^? A
exclusitivity constraint: . . .
exhaustion constraint: . . .
extension of: A logic L' is an extension of logic L iff everything valid in L is valid in L'.
law of excluded middle: B ⊢ A ∨ ¬A
law of non-contradiction: A ∧ ¬A ⊢ B
logical consequence: . . .
logical truth: . . .
material identity: B ⊢ A ⊃ A
modus ponens: A → B, A ⊢ B
modus tollens: A → B, ¬B ⊢ A
truth-functional operator: . . .