status#set_stack gstatus
;;
-let branch_tac status =
+let branch_tac ?(force=false) status =
let gstatus =
match status#stack with
| [] -> assert false
| (g, t, k, tag) :: s ->
match init_pos g with (* TODO *)
- | [] | [ _ ] -> fail (lazy "too few goals to branch");
+ | [] -> fail (lazy "empty goals")
+ | [_] when (not force) -> fail (lazy "too few goals to branch")
| loc :: loc_tl ->
([ loc ], [], [], `BranchTag) :: (loc_tl, t, k, tag) :: s
in
}
;;
+let ref_of_indtyinfo iti = iti.reference;;
+
let analyze_indty_tac ~what indtyref =
distribute_tac (fun status goal ->
let goalty = get_goalty status goal in
| [seq] -> assert0_tac seq
| _ ->
block_tac
- (branch_tac::
+ ((branch_tac ~force:false)::
HExtlib.list_concat ~sep:[shift_tac]
(List.map (fun seq -> [assert0_tac seq]) seqs)@
[merge_tac])
) status
;;
+let inversion_tac ~what:(txt,len,what) ~where =
+ let what = txt, len, Ast.Appl [what; Ast.Implicit `Vector] in
+ let indtyinfo = ref None in
+ let sort = ref (NCic.Rel 1) in
+ atomic_tac (block_tac [
+ analyze_indty_tac ~what indtyinfo;
+ (fun s -> select_tac
+ ~where ~job:(`Substexpand ((HExtlib.unopt !indtyinfo).rightno+1)) true s);
+ sort_of_goal_tac sort;
+ (fun status ->
+ let ity = HExtlib.unopt !indtyinfo in
+ let NReference.Ref (uri, _) = ity.reference in
+ let name =
+ NUri.name_of_uri uri ^ "_inv_" ^
+ snd (NCicElim.ast_of_sort
+ (match !sort with NCic.Sort x -> x | _ -> assert false))
+ in
+ let eliminator =
+ let _,_,w = what in
+ Ast.Appl [ Ast.Ident (name,None) ; Ast.Implicit `Vector ; w ]
+ in
+ exact_tac ("",0,eliminator) status) ])
+;;