#   Set: pp::colors
  Set: pp::unicode
Proof state:
a : Bool, b : Bool, H : a, H::1 : b ⊢ a ∧ b
## Error (line: 5, pos: 0) invalid 'done' command, proof cannot be produced from this state
Proof state:
a : Bool, b : Bool, H : a, H::1 : b ⊢ a ∧ b
## Error (line: 6, pos: 0) invalid 'done' command, proof cannot be produced from this state
Proof state:
a : Bool, b : Bool, H : a, H::1 : b ⊢ a ∧ b
## Error (line: 7, pos: 0) unknown tactic 'imp_tac2'
## Error (line: 8, pos: 0) unknown tactic 'foo'
## Proof state:
a : Bool, b : Bool, H : a, H::1 : b ⊢ a
a : Bool, b : Bool, H : a, H::1 : b ⊢ b
## Error (line: 10, pos: 0) failed to backtrack
Proof state:
a : Bool, b : Bool, H : a, H::1 : b ⊢ a
a : Bool, b : Bool, H : a, H::1 : b ⊢ b
## Proof state:
no goals
##   Proved: T2
#