Full Idea
The classical semantics of natural language propositions says 1) valid arguments preserve truth, 2) no statement is both true and false, 3) each statement is either true or false, 4) the familiar truth tables.
Gist of Idea
Semantics for propositions: 1) validity preserves truth 2) non-contradition 3) bivalence 4) truth tables
Source
Ian Rumfitt (The Boundary Stones of Thought [2015], 1.1)
Book Reference
Rumfitt,Ian: 'The Boundary Stones of Thought' [OUP 2015], p.10