Proof Theory
Transformational Proof
Natural Deduction
Semantic Tableaux
Proof theories
provide means of “calculating” things about the logic. Each proof theory is a means of doing proofs in that logic.
Proof theories:
- defineds (pronounced “proves”)
- methods that perform mechanical manipulations on strings of symbols.
- based on pattern matching
- multiple ways to prove a formula
Goals (sequents): if we aren’t yet sure they are valid or proven. Theorems (problems): if they have been determined to be valid or been proven.