Full Idea
'For every number x, x = x' is not a tautology, because it includes no connectives.
Gist of Idea
A 'tautology' must include connectives
Source
Robert S. Wolf (A Tour through Mathematical Logic [2005], 1.2)
Book Reference
Wolf,Robert S.: 'A Tour Through Mathematical Logic' [Carus Maths Monographs 2005], p.11
Related Idea
Idea 9528 A wff is a 'tautology' if all assignments to variables result in the value T [Lemmon]