#   Set: pp::colors
  Set: pp::unicode
Proof state:
a : Bool, b : Bool, H : a, H::1 : b ⊢ a ∧ b
## stdin:5:0 error: invalid 'done' command, proof cannot be produced from this state
Proof state:
a : Bool, b : Bool, H : a, H::1 : b ⊢ a ∧ b
## stdin:6:0 error: invalid 'done' command, proof cannot be produced from this state
Proof state:
a : Bool, b : Bool, H : a, H::1 : b ⊢ a ∧ b
## stdin:7:0 error: unknown tactic 'imp_tac2'
## stdin:8:0 error: 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
## stdin:10:0 error: 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
#