michael/lean2
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

fix(library/simplifier): bug in cast elimination

Browse source 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
This commit is contained in:
Leonardo de Moura 2014-01-24 21:25:09 -08:00
parent 2bb33c55fe
commit c2381e43f1
3 changed files with 55 additions and 2 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

6
src/library/simplifier/simplifier.cpp
View file

@ -347,6 +347,8 @@ class simplifier_fn {
result simplify_app(expr const & e) {
if (m_has_cast && is_cast(e)) {
// e is of the form (cast A B H a)
// a : A
// e : B
expr A = arg(e, 1);
expr B = arg(e, 2);
expr H = arg(e, 3);
@ -358,11 +360,11 @@ class simplifier_fn {
expr Hec;
expr Hac = *res_a.m_proof;
if (!res_a.m_heq_proof) {
Hec = ::lean::mk_htrans_th(A, B, B, e, a, c,
Hec = ::lean::mk_htrans_th(B, A, A, e, a, c,
update_app(e, 0, mk_cast_heq_fn()), // cast A B H a == a
mk_to_heq_th(B, a, c, Hac)); // a == c
} else {
Hec = ::lean::mk_htrans_th(A, B, infer_type(c), e, a, c,
Hec = ::lean::mk_htrans_th(B, A, infer_type(c), e, a, c,
update_app(e, 0, mk_cast_heq_fn()), // cast A B H a == a
Hac); // a == c
}

32
tests/lean/simp23.lean Normal file
View file

@ -0,0 +1,32 @@
import cast
variable vec : Nat → Type
variable concat {n m : Nat} (v : vec n) (w : vec m) : vec (n + m)
infixl 65 ; : concat
axiom concat_assoc {n1 n2 n3 : Nat} (v1 : vec n1) (v2 : vec n2) (v3 : vec n3) :
(v1 ; v2) ; v3 = cast (congr2 vec (symm (Nat::add_assoc n1 n2 n3)))
(v1 ; (v2 ; v3))
variable empty : vec 0
axiom concat_empty {n : Nat} (v : vec n) :
v ; empty = cast (congr2 vec (symm (Nat::add_zeror n)))
v
rewrite_set simple
add_rewrite concat_assoc concat_empty Nat::add_assoc Nat::add_zeror and_truer eq_id : simple
variable n : Nat
variable v : vec n
variable w : vec n
variable f {A : TypeM} : A → A
variable p {A : TypeM} : A → Bool
axiom fax {n m : Nat} (v : vec n) (w : vec m) : f (v; (w; v)) = v; (w; v)
add_rewrite fax : simple
(*
local t = parse_lean([[ p (f ((v ; w) ; empty ; (v ; empty))) ∧ v = cast (congr2 vec (Nat::add_zeror n)) (v ; empty) ]])
print(t)
print("===>")
local t2, pr = simplify(t, "simple")
print(t2)
print("checking proof")
print (get_environment():type_check(pr))
*)

19
tests/lean/simp23.lean.expected.out Normal file
View file

@ -0,0 +1,19 @@
Set: pp::colors
Set: pp::unicode
Imported 'cast'
Assumed: vec
Assumed: concat
Assumed: concat_assoc
Assumed: empty
Assumed: concat_empty
Assumed: n
Assumed: v
Assumed: w
Assumed: f
Assumed: p
Assumed: fax
p (f (v ; w ; empty ; (v ; empty))) ∧ v = cast (congr2 vec (Nat::add_zeror n)) (v ; empty)
===>
p (v ; (w ; v))
checking proof
(p (f (v ; w ; empty ; (v ; empty))) ∧ v = cast (congr2 vec (Nat::add_zeror n)) (v ; empty)) == p (v ; (w ; v))