pl/frap
1
0
Fork 0
mirror of https://github.com/achlipala/frap.git synced 2024-11-28 07:16:20 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

Avoid a notation conflict

Browse source
This commit is contained in:
Adam Chlipala 2016-02-25 11:54:03 -05:00
parent a583e1d0d4
commit 4889f08ac4
1 changed files with 13 additions and 13 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

26
OperationalSemantics.v
View file

@ -37,13 +37,13 @@ Infix "*" := Times : arith_scope.
Delimit Scope arith_scope with arith.
Notation "x <- e" := (Assign x e%arith) (at level 75).
Infix ";;" := Sequence (at level 76). (* This one changed slightly, to avoid parsing clashes. *)
Notation "'when' e 'do' then_ 'else' else_ 'done'" := (If e%arith then_ else_) (at level 75, e at level 0).
Notation "'while' e 'do' body 'done'" := (While e%arith body) (at level 75).
Notation "'when' e 'loop' then_ 'else' else_ 'done'" := (If e%arith then_ else_) (at level 75, e at level 0).
Notation "'while' e 'loop' body 'done'" := (While e%arith body) (at level 75).
(* Here's an adaptation of our factorial example from Chapter 3. *)
Example factorial :=
"output" <- 1;;
while "input" do
while "input" loop
"output" <- "output" * "input";;
"input" <- "input" - 1
done.
@ -159,7 +159,7 @@ Fixpoint fact (n : nat) : nat :=
end.
Example factorial_loop :=
while "input" do
while "input" loop
"output" <- "output" * "input";;
"input" <- "input" - 1
done.
@ -518,13 +518,13 @@ Inductive isEven : nat -> Prop :=
| EvenSS : forall n, isEven n -> isEven (S (S n)).
Definition my_loop :=
while "n" do
while "n" loop
"a" <- "a" + "n";;
"n" <- "n" - 2
done.
Definition all_programs := {
(while "n" do
(while "n" loop
"a" <- "a" + "n";;
"n" <- "n" - 2
done),
@ -535,23 +535,23 @@ Definition all_programs := {
("n" <- "n" - 2),
(("a" <- "a" + "n";;
"n" <- "n" - 2);;
while "n" do
while "n" loop
"a" <- "a" + "n";;
"n" <- "n" - 2
done),
((Skip;;
"n" <- "n" - 2);;
while "n" do
while "n" loop
"a" <- "a" + "n";;
"n" <- "n" - 2
done),
("n" <- "n" - 2;;
while "n" do
while "n" loop
"a" <- "a" + "n";;
"n" <- "n" - 2
done),
(Skip;;
while "n" do
while "n" loop
"a" <- "a" + "n";;
"n" <- "n" - 2
done),
@ -583,7 +583,7 @@ Proof.
Qed.
Lemma manually_proved_invariant' :
invariantFor (trsys_of ($0 $+ ("n", 0) $+ ("a", 0)) (while "n" do "a" <- "a" + "n";; "n" <- "n" - 2 done))
invariantFor (trsys_of ($0 $+ ("n", 0) $+ ("a", 0)) (while "n" loop "a" <- "a" + "n";; "n" <- "n" - 2 done))
(fun s => all_programs (snd s)
/\ exists n a, fst s $? "n" = Some n
/\ fst s $? "a" = Some a
@ -680,7 +680,7 @@ Hint Constructors isEven.
Hint Resolve isEven_minus2 isEven_plus.
Lemma manually_proved_invariant'_snazzy :
invariantFor (trsys_of ($0 $+ ("n", 0) $+ ("a", 0)) (while "n" do "a" <- "a" + "n";; "n" <- "n" - 2 done))
invariantFor (trsys_of ($0 $+ ("n", 0) $+ ("a", 0)) (while "n" loop "a" <- "a" + "n";; "n" <- "n" - 2 done))
(fun s => all_programs (snd s)
/\ exists n a, fst s $? "n" = Some n
/\ fst s $? "a" = Some a
@ -700,7 +700,7 @@ Proof.
Qed.
Theorem manually_proved_invariant :
invariantFor (trsys_of ($0 $+ ("n", 0) $+ ("a", 0)) (while "n" do "a" <- "a" + "n";; "n" <- "n" - 2 done))
invariantFor (trsys_of ($0 $+ ("n", 0) $+ ("a", 0)) (while "n" loop "a" <- "a" + "n";; "n" <- "n" - 2 done))
(fun s => exists a, fst s $? "a" = Some a /\ isEven a).
Proof.
eapply invariant_weaken.