Set: pp::colors
Set: pp::unicode
Imported 'tactic'
Proved: T1
Proved: T2
Theorem T2 (a b : Bool) : a ∨ b ⇒ b ∨ a :=
Discharge (λ H : a ∨ b, DisjCases H (λ H : a, Disj2 b H) (λ H : b, Disj1 a H))