Goal:
    A : Type  d : A  v : A  H : d = v
  ============================
   ((None = Some v) + (None = None ∧ v = d))%type


DEBUG:Going to execute:
match goal with
           | H:¬ _ |- _ => solve [ case H; trivial ]
           end
Level 1: Backtrace:

No such assumption.
Level 0: Backtrace:

No such assumption.
Level 0: Backtrace:

No such assumption.
Level 0: Backtrace:

No such assumption.