+ let to_s =
+ NCicCoercion.look_for_coercion status [] [] [] (NCic.Implicit `Type) s
+ in
+ let from_d =
+ NCicCoercion.look_for_coercion status [] [] [] d (NCic.Implicit `Type)
+ in
+ let status = NCicCoercion.index_coercion status t s d a p in
+ let c =
+ List.find
+ (function (_,NCic.Appl (x::_),_,_) -> x = t | _ -> assert false)
+ (NCicCoercion.look_for_coercion status [] [] [] s d)
+ in
+ let composites =
+ let to_s_o_c =
+ product (fun (m1,t1,_,j) (mc,c,_,i) -> m1@mc,c,[i,t1],j,a)
+ to_s [c]
+ in
+ let c_o_from_d =
+ product (fun (mc,c,_,j) (m1,t1,ty,i) -> m1@mc,t1,[i,c],j,count_prod ty)
+ [c] from_d
+ in
+ let to_s_o_c_o_from_d =
+ product (fun (m1,t1,_,j) (m,t,upl,i,a)->
+ m@m1,t,(i,t1)::upl,j,a)
+ to_s c_o_from_d
+ in
+ to_s_o_c @ c_o_from_d @ to_s_o_c_o_from_d
+ in
+ let composites =
+ HExtlib.filter_map
+ (fun (metasenv, bo, upl, p, arity) ->
+ try
+ let metasenv, subst =
+ List.fold_left
+ (fun (metasenv,subst) (a,b) ->
+ NCicUnification.unify status metasenv subst [] a b)
+ (metasenv,[]) upl
+ in
+ let bo = NCicUntrusted.apply_subst subst [] bo in
+ let metasenv = toposort metasenv in
+ let bo = close_in_context bo metasenv in
+ let pos =
+ match p with
+ | NCic.Meta (p,_) -> pos_in_list p (List.map fst metasenv)
+ | _ -> assert false
+ in
+ let ty = NCicTypeChecker.typeof ~metasenv:[] ~subst:[] [] bo in
+ let src,tgt = src_tgt_of_ty_cpos_arity ty pos arity in
+ prerr_endline (
+ NCicPp.ppterm ~metasenv:[] ~subst:[] ~context:[] bo ^ " : " ^
+ NCicPp.ppterm ~metasenv:[] ~subst:[] ~context:[] ty ^ " as " ^
+ NCicPp.ppterm ~metasenv:[] ~subst:[] ~context:[] src ^ " ===> " ^
+ NCicPp.ppterm ~metasenv:[] ~subst:[] ~context:[] tgt ^
+ " cpos=" ^ string_of_int pos ^ " arity=" ^ string_of_int arity);
+ Some (bo,src,tgt,arity,pos)
+ with
+ | NCicTypeChecker.TypeCheckerFailure _
+ | NCicUnification.UnificationFailure _
+ | NCicUnification.Uncertain _ -> None
+ ) composites
+ in
+ List.fold_left
+ (fun st (t,s,d,a,p) -> NCicCoercion.index_coercion st t s d a p)
+ status composites