Question

是否存在一些Coq策略来防止生成多个相同的子目标？如果不是，是否有可能写出某种策略在生成子目标之后立即消除它们？在Isabelle中，您可以执行以下操作：

apply (tactic {* distinct_subgoals_tac *})

Answer 1

在不编写OCaml代码的情况下，不可能在事后消除重复，但是您可以创建一个evar，该evar是所有重复数据消除后的子目标的结合。像这样：

Ltac distinct_subgoals_tactical tac :=
  let H := fresh in
  unshelve epose proof _ as H;
  [ |
  | tac;
    [ (* first split apart the hypothesis containing the conjunction of all previous subgoals *)
      repeat match type of H with prod _ _ => destruct H as [? H] end;
      (* see if any of them solve the goal *)
      try assumption;
      (* otherwise, add another conjunct to the hypothesis and use the first part of it to solve the current goal *)
      refine (fst H) .. ] ];
    [ exact True (* fill the final conjunct with True *)
    | repeat apply pair; try exact I .. ].

然后您可以将其作为distinct_subgoals_tactical ltac:(<apply tactic here>)

来调用

Coq中的子目标重复

1 个答案: