#   Set: pp::colors
  Set: pp::unicode
Proof state:
a : Bool, b : Bool ⊢ b ⇒ a ∨ b
## Proof state:
H : b, a : Bool, b : Bool ⊢ a ∨ b
## Proof state:
H : b, a : Bool, b : Bool ⊢ a
## Proof state:
H : b, a : Bool, b : Bool ⊢ b
## Error (line: 10, pos: 0) failed to backtrack
Proof state:
H : b, a : Bool, b : Bool ⊢ b
## Proof state:
no goals
##   Proved: T2
# theorem T2 (a b : Bool) : b ⇒ a ∨ b := discharge (λ H : b, or::intror a H)
#