Goal:
  
  A : Type
  B : Type
  C : Type
  Q : C → Type
  P : C → A → Prop
  fn : ∀ x : A, (∀ y : C, Q y → P y x) → B
  Hl : ∀ y : C, Q y → ∥ All (P y) [] ∥
  x : A
  ============================
   (Some x = None
    → let H := CoreTactics.block in
      let H0 := CoreTactics.block in
      ∃ D : ∀ y : C, Q y → P y x,
        nth_error (map_All fn [] Hl) 0 = Some (fn x D))


DEBUG:Going to execute:
<coq-equations.plugin::simplify@0> $1

Goals:

DEBUG:Going to execute:
cbv beta

Goals:

DEBUG:Going to execute:
DepElim.simplify_IH_hyps

Goals:

DEBUG:Going to execute:
repeat
            match goal with
            | hyp:context [ CoreTactics.block ]
              |- _ =>
                  cbn beta in hyp; eqns_specialize_eqs_block hyp;
                   cbn[eq_rect_r eq_rect] in hyp
            end

Goals:

DEBUG:Going to execute:
DepElim.unblock_dep_elim

Goals:

DEBUG:Going to execute:
match goal with
           | |- let _ := CoreTactics.block in ?T =>
                 match T with
                 | context [ CoreTactics.block ] =>
                     change T; CoreTactics.intros_until_block
                 end
           | _ => CoreTactics.unblock_goal
           end

Goals:

DEBUG:Going to execute:
CoreTactics.unblock_goal

Goals:

DEBUG:Going to execute:
unfold CoreTactics.block in *; cbv zeta

Goals:

DEBUG:Going to execute:
unfold CoreTactics.block in *

Goals:

DEBUG:Going to execute:
cbv zeta