Commit 8e62fc12 authored by Andrei Paskevich's avatar Andrei Paskevich
Browse files

check for runaway type variables in definitions

parent 9e66b348
......@@ -47,12 +47,20 @@ let check_vl ty v = ty_equal_check ty v.vs_ty
let check_tl ty t = ty_equal_check ty (t_type t)
let make_ls_defn ls vl t =
(* build the definition axiom *)
let hd = t_app ls ( t_var vl) t.t_ty in
let hd = TermTF.t_selecti t_equ t_iff hd t in
let fd = t_forall_close vl [] hd in
let bd = TermTF.t_selecti t_equ t_iff hd t in
let fd = check_fvs (t_forall_close vl [] bd) in
(* check for unbound type variables *)
let htv = t_ty_freevars Stv.empty hd in
let ttv = t_ty_freevars Stv.empty t in
if not (Stv.subset ttv htv) then
raise (UnboundTypeVar (Stv.choose (Stv.diff ttv htv)));
(* check correspondence with the type signature of ls *)
List.iter2 check_vl ls.ls_args vl;
t_ty_check t ls.ls_value;
ls, Some (ls, check_fvs fd)
(* return the definition *)
ls, Some (ls, fd)
let open_ls_defn (_,f) =
let vl,_,f = match f.t_node with
......@@ -460,12 +468,17 @@ let create_ind_decl idl =
| Tbinop (Timplies, g, f) -> clause (g::acc) f
| _ -> (acc, f)
let cls, f = clause [] (check_fvs f) in
match f.t_node with
let cls, g = clause [] (check_fvs f) in
match g.t_node with
| Tapp (s, tl) when ls_equal s ps ->
List.iter2 check_tl ps.ls_args tl;
(try ignore (List.for_all (f_pos_ps sps (Some true)) cls)
with Found ls -> raise (NonPositiveIndDecl (ps, pr, ls)));
(* check for unbound type variables *)
let gtv = t_ty_freevars Stv.empty g in
let ftv = t_ty_freevars Stv.empty f in
if not (Stv.subset ftv gtv) then
raise (UnboundTypeVar (Stv.choose (Stv.diff ftv gtv)));
syms_term syms f, news_id news pr.pr_name
| _ -> raise (InvalidIndDecl (ps, pr))
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