mirror of
https://github.com/achlipala/frap.git
synced 2024-11-27 23:06:20 +00:00
Update LogicProgramming for Coq 8.10
This commit is contained in:
parent
d6e8cebdc9
commit
096b69a3e9
2 changed files with 31 additions and 31 deletions
|
@ -44,7 +44,7 @@ Qed.
|
|||
* automate searching through sequences of that kind, when we prime it with good
|
||||
* suggestions of single proof steps to try, as with this command: *)
|
||||
|
||||
Hint Constructors plusR.
|
||||
Hint Constructors plusR : core.
|
||||
|
||||
(* That is, every constructor of [plusR] should be considered as an atomic proof
|
||||
* step, from which we enumerate step sequences. *)
|
||||
|
@ -205,7 +205,7 @@ SearchRewrite (O + _).
|
|||
* as a candidate step for any leaf of a proof tree, meaning that all premises
|
||||
* of the rule need to match hypotheses. *)
|
||||
|
||||
Hint Immediate plus_O_n.
|
||||
Hint Immediate plus_O_n : core.
|
||||
|
||||
(* The counterpart to [PlusS] we will prove ourselves. *)
|
||||
|
||||
|
@ -219,7 +219,7 @@ Qed.
|
|||
(* The command [Hint Resolve] adds a new candidate proof step, to be attempted
|
||||
* at any level of a proof tree, not just at leaves. *)
|
||||
|
||||
Hint Resolve plusS.
|
||||
Hint Resolve plusS : core.
|
||||
|
||||
(* Now that we have registered the proper hints, we can replicate our previous
|
||||
* examples with the normal, functional addition [plus]. *)
|
||||
|
@ -251,7 +251,7 @@ Proof.
|
|||
linear_arithmetic.
|
||||
Qed.
|
||||
|
||||
Hint Resolve plusO.
|
||||
Hint Resolve plusO : core.
|
||||
|
||||
(* Note that, if we consider the inputs to [plus] as the inputs of a
|
||||
* corresponding logic program, the new rule [plusO] introduces an ambiguity.
|
||||
|
@ -276,7 +276,7 @@ Check eq_trans.
|
|||
* effects of an unfortunate hint choice. *)
|
||||
|
||||
Section slow.
|
||||
Hint Resolve eq_trans.
|
||||
Hint Resolve eq_trans : core.
|
||||
|
||||
(* The following fact is false, but that does not stop [eauto] from taking a
|
||||
* very long time to search for proofs of it. We use the handy [Time] command
|
||||
|
@ -367,7 +367,7 @@ Proof.
|
|||
simplify; equality.
|
||||
Qed.
|
||||
|
||||
Hint Resolve length_O length_S.
|
||||
Hint Resolve length_O length_S : core.
|
||||
|
||||
(* Let us apply these hints to prove that a [list nat] of length 2 exists.
|
||||
* (Here we register [length_O] with [Hint Resolve] instead of [Hint Immediate]
|
||||
|
@ -383,9 +383,9 @@ Proof.
|
|||
* type were left undetermined, by the end of the proof. Specifically, these
|
||||
* variables stand for the 2 elements of the list we find. Of course it makes
|
||||
* sense that the list length follows without knowing the data values. In Coq
|
||||
* 8.6, the [Unshelve] command brings these goals to the forefront, where we
|
||||
* can solve each one with [exact O], but usually it is better to avoid
|
||||
* getting to such a point.
|
||||
* 8.6 and up, the [Unshelve] command brings these goals to the forefront,
|
||||
* where we can solve each one with [exact O], but usually it is better to
|
||||
* avoid getting to such a point.
|
||||
*
|
||||
* To debug such situations, it can be helpful to print the current internal
|
||||
* representation of the proof, so we can see where the unification variables
|
||||
|
@ -424,17 +424,17 @@ Proof.
|
|||
linear_arithmetic.
|
||||
Qed.
|
||||
|
||||
Hint Resolve plusO'.
|
||||
Hint Resolve plusO' : core.
|
||||
|
||||
(* Finally, we meet [Hint Extern], the command to register a custom hint. That
|
||||
* is, we provide a pattern to match against goals during proof search.
|
||||
* Whenever the pattern matches, a tactic (given to the right of an arrow [=>])
|
||||
* is attempted. Below, the number [1] gives a priority for this step. Lower
|
||||
* priorities are tried before higher priorities, which can have a significant
|
||||
* effect on proof search time, i.e. when we manage to give lower priorities to
|
||||
* effect on proof-search time, i.e. when we manage to give lower priorities to
|
||||
* the cheaper rules. *)
|
||||
|
||||
Hint Extern 1 (sum _ = _) => simplify.
|
||||
Hint Extern 1 (sum _ = _) => simplify : core.
|
||||
|
||||
(* Now we can find a length-2 list whose sum is 0. *)
|
||||
|
||||
|
@ -497,7 +497,7 @@ Inductive eval (var : nat) : exp -> nat -> Prop :=
|
|||
-> eval var e2 n2
|
||||
-> eval var (Plus e1 e2) (n1 + n2).
|
||||
|
||||
Hint Constructors eval.
|
||||
Hint Constructors eval : core.
|
||||
|
||||
(* We can use [auto] to execute the semantics for specific expressions. *)
|
||||
|
||||
|
@ -531,13 +531,13 @@ Proof.
|
|||
simplify; subst; auto.
|
||||
Qed.
|
||||
|
||||
Hint Resolve EvalPlus'.
|
||||
Hint Resolve EvalPlus' : core.
|
||||
|
||||
(* Further, we instruct [eauto] to apply [ring], via [Hint Extern]. We should
|
||||
* try this step for any equality goal. *)
|
||||
|
||||
Section use_ring.
|
||||
Hint Extern 1 (_ = _) => ring.
|
||||
Hint Extern 1 (_ = _) => ring : core.
|
||||
|
||||
(* Now we can return to [eval1'] and prove it automatically. *)
|
||||
|
||||
|
@ -597,7 +597,7 @@ Proof.
|
|||
simplify; subst; auto.
|
||||
Qed.
|
||||
|
||||
Hint Resolve EvalConst' EvalVar'.
|
||||
Hint Resolve EvalConst' EvalVar' : core.
|
||||
|
||||
(* Next, we prove a few hints that feel a bit like cheating, as they telegraph
|
||||
* the procedure for choosing values of [k] and [n]. Nonetheless, with these
|
||||
|
@ -629,7 +629,7 @@ Section cheap_hints.
|
|||
simplify; ring.
|
||||
Qed.
|
||||
|
||||
Hint Resolve zero_times plus_0 times_1 combine.
|
||||
Hint Resolve zero_times plus_0 times_1 combine : core.
|
||||
|
||||
Theorem linear : forall e, exists k n,
|
||||
forall var, eval var e (k * var + n).
|
||||
|
@ -673,14 +673,14 @@ Ltac robust_ring_simplify :=
|
|||
|
||||
(* This tactic is pretty expensive, but let's try it eventually whenever the
|
||||
* goal is an equality. *)
|
||||
Hint Extern 5 (_ = _) => robust_ring_simplify.
|
||||
Hint Extern 5 (_ = _) => robust_ring_simplify : core.
|
||||
|
||||
(* The only other missing ingredient is priming Coq with some good ideas for
|
||||
* instantiating existential quantifiers. These will all be tried in some
|
||||
* order, in a particular proof search. *)
|
||||
Hint Extern 1 (exists n : nat, _) => exists 0.
|
||||
Hint Extern 1 (exists n : nat, _) => exists 1.
|
||||
Hint Extern 1 (exists n : nat, _) => eexists (_ + _).
|
||||
Hint Extern 1 (exists n : nat, _) => exists 0 : core.
|
||||
Hint Extern 1 (exists n : nat, _) => exists 1 : core.
|
||||
Hint Extern 1 (exists n : nat, _) => eexists (_ + _) : core.
|
||||
(* Note how this last hint uses [eexists] to provide an instantiation with
|
||||
* wildcards inside it. Each underscore is replaced with a fresh unification
|
||||
* variable. *)
|
||||
|
@ -695,9 +695,9 @@ Qed.
|
|||
(* Here's a quick tease using a feature that we'll explore fully in a later
|
||||
* class. Let's use a mysterious construct [sigT] instead of [exists]. *)
|
||||
|
||||
Hint Extern 1 (sigT (fun n : nat => _)) => exists 0.
|
||||
Hint Extern 1 (sigT (fun n : nat => _)) => exists 1.
|
||||
Hint Extern 1 (sigT (fun n : nat => _)) => eexists (_ + _).
|
||||
Hint Extern 1 (sigT (fun n : nat => _)) => exists 0 : core.
|
||||
Hint Extern 1 (sigT (fun n : nat => _)) => exists 1 : core.
|
||||
Hint Extern 1 (sigT (fun n : nat => _)) => eexists (_ + _) : core.
|
||||
|
||||
Theorem linear_computable : forall e, sigT (fun k => sigT (fun n =>
|
||||
forall var, eval var e (k * var + n))).
|
||||
|
@ -745,7 +745,7 @@ Section side_effect_sideshow.
|
|||
Qed.
|
||||
|
||||
(* That was easy enough. [eauto] could have solved the whole thing, but humor
|
||||
* me by considering this slightly less automated proof. Watch what happens
|
||||
* me by considering this slightly less-automated proof. Watch what happens
|
||||
* when we add a new premise. *)
|
||||
|
||||
Variable z : A.
|
||||
|
@ -814,7 +814,7 @@ Abort.
|
|||
* restatement of the theorem we mean to prove. Luckily, a simpler form
|
||||
* suffices, by appealing to the [equality] tactic. *)
|
||||
|
||||
Hint Extern 1 (_ <> _) => equality.
|
||||
Hint Extern 1 (_ <> _) => equality : core.
|
||||
|
||||
Theorem bool_neq : true <> false.
|
||||
Proof.
|
||||
|
@ -843,7 +843,7 @@ Section forall_and.
|
|||
Hint Extern 1 (P ?X) =>
|
||||
match goal with
|
||||
| [ H : forall x, P x /\ _ |- _ ] => apply (proj1 (H X))
|
||||
end.
|
||||
end : core.
|
||||
|
||||
auto.
|
||||
Qed.
|
||||
|
@ -859,7 +859,7 @@ End forall_and.
|
|||
Fail Hint Extern 1 (?P ?X) =>
|
||||
match goal with
|
||||
| [ H : forall x, P x /\ _ |- _ ] => apply (proj1 (H X))
|
||||
end.
|
||||
end : core.
|
||||
|
||||
(* Coq's [auto] hint databases work as tables mapping _head symbols_ to lists of
|
||||
* tactics to try. Because of this, the constant head of an [Extern] pattern
|
||||
|
@ -874,7 +874,7 @@ Fail Hint Extern 1 (?P ?X) =>
|
|||
Hint Extern 1 =>
|
||||
match goal with
|
||||
| [ H : forall x, ?P x /\ _ |- ?P ?X ] => apply (proj1 (H X))
|
||||
end.
|
||||
end : core.
|
||||
|
||||
(* Be forewarned that a [Hint Extern] of this kind will be applied at _every_
|
||||
* node of a proof tree, so an expensive Ltac script may slow proof search
|
||||
|
|
|
@ -83,7 +83,7 @@ Admitted.
|
|||
Check eq_trans.
|
||||
|
||||
Section slow.
|
||||
Hint Resolve eq_trans.
|
||||
Hint Resolve eq_trans : core.
|
||||
|
||||
Example zero_minus_one : exists x, 1 + x = 0.
|
||||
Time eauto 1.
|
||||
|
@ -173,7 +173,7 @@ Inductive eval (var : nat) : exp -> nat -> Prop :=
|
|||
-> eval var e2 n2
|
||||
-> eval var (Plus e1 e2) (n1 + n2).
|
||||
|
||||
Hint Constructors eval.
|
||||
Hint Constructors eval : core.
|
||||
|
||||
Example eval1 : forall var, eval var (Plus Var (Plus (Const 8) Var)) (var + (8 + var)).
|
||||
Proof.
|
||||
|
|
Loading…
Reference in a new issue