Tautologies?

Question

there where no sections on philosophy so i have posted this question here and under maths

i am unsure so plez correct me if im wrong.

there is only one rule tautologys follow
- a tautology is only true if it contains no contradiction.

yet that rule is built using tautology,
i therefore ask is the non-contradiction tautology the tautology of tautology's.

Answer 1

this question hurts my brain.