Do I finally have a good definition of a "tautology?" For some reason, that one always eludes me.
“A tautology is a tautology”...is a tautology. :)
4 = 4 is a tautology and so is 2 + 2 = 4.
Sometimes they are trivial and sometimes it takes a little work to realize that the 2 expressions are indeed the same, the definition of a tautology.