Tautology (Redundancy)
This video presents the same text shown beside it, spoken and on screen. It adds nothing the text does not say.
State
p :: p ∨ p, and p :: p · p.
Show
Repetition adds nothing and can be collapsed — or manufactured.
Watch for
Mostly used at the end of dilemma proofs, collapsing q ∨ q into q. Blink and you'll miss needing it.