Proof
A proof is a sequence of true statements without logical gaps, that establishes some conclusions.
Definition 1.2 (Proof)
A proof is a sequence of true statements without logical gaps, that establishes some conclusions.
Disproof and contradiction
A false claim is disproved by a counterexample: disproves that being a multiple of 9 implies is a multiple of 9. A purported argument may instead establish only the converse of the claimed statement, which proves nothing about the claim itself. In proof by contradiction, one assumes the contrary of what is to be shown and deduces a contradiction, so the assumption must be false.
Related
Stated in
- Definition 1.2 (Proof)§1 Introduction to Number Systems and Logic