Goal:
    A : Type
  ============================
   (option_map id None = id None)


DEBUG:Going to execute:
<coq-core.plugins.ltac::trivial@0> $1 $2

Goals:

DEBUG:Going to execute:
hnf

Goals:

DEBUG:Going to execute:
intros

Goals:

DEBUG:Going to execute:
solve
[ do
![ solve
 [ trivial | apply : eq_sym ; trivial ]
 | discriminate
 | contradiction
 | split ]
| case not_locked_false_eq_true; assumption
| match goal with
  | H:~ _ |- _ => solve [ case H; trivial ]
  end ]