Propositions that have the same truth value.
Synonym for identity.
The equivalence of the two propositions P and Q is noted as: P \(\iff\) Q and is read as: “P is equivalent to Q” or “P if and only if Q”.
- For the real values of x, the following propositions are equivalent:
4x + 2 = 12 \(\iff\) x = 2.5.
- “The triangles ABC and DEF are similar” \(\iff\) “The corresponding angles of triangles ABC and DEF are isometric”.