Single Idea 13524

[catalogued under 4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / c. Derivation rules of PL]

Full Idea

Deduction Theorem: If T ∪ {P} |- Q, then T |- (P → Q). This is the formal justification of the method of conditional proof (CPP). Its converse holds, and is essentially modus ponens.

Gist of Idea

Deduction Theorem: T∪{P}|-Q, then T|-(P→Q), which justifies Conditional Proof

Source

Robert S. Wolf (A Tour through Mathematical Logic [2005], 1.3)

Book Reference

Wolf,Robert S.: 'A Tour Through Mathematical Logic' [Carus Maths Monographs 2005], p.31