(************************************************************************)
(*  v      *   The Coq Proof Assistant  /  The Coq Development Team     *)
(* <O___,, * CNRS-Ecole Polytechnique-INRIA Futurs-Universite Paris Sud *)
(*   \VV/  **************************************************************)
(*    //   *      This file is distributed under the terms of the       *)
(*         *       GNU Lesser General Public License Version 2.1        *)
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(*i $Id: inductive.mli,v 1.57.8.2 2005/01/21 16:41:49 herbelin Exp $ i*)

(*i*)
open Names
open Univ
open Term
open Declarations
open Environ
(*i*)

(*s Extracting an inductive type from a construction *)

(* [find_m*type env sigma c] coerce [c] to an recursive type (I args).
   [find_rectype], [find_inductive] and [find_coinductive]
   respectively accepts any recursive type, only an inductive type and
   only a coinductive type.
   They raise [Not_found] if not convertible to a recursive type. *)

val find_rectype     : env -> types -> inductive * constr list
val find_inductive   : env -> types -> inductive * constr list
val find_coinductive : env -> types -> inductive * constr list

(*s Fetching information in the environment about an inductive type.
    Raises [Not_found] if the inductive type is not found. *)
val lookup_mind_specif :
  env -> inductive -> mutual_inductive_body * one_inductive_body

(*s Functions to build standard types related to inductive *)

val type_of_inductive    : env -> inductive -> types

(* Return type as quoted by the user *)
val type_of_constructor  : env -> constructor -> types

(* Return constructor types in normal form *)
val arities_of_constructors : env -> inductive -> types array

(* Transforms inductive specification into types (in nf) *)
val arities_of_specif : mutual_inductive -> 
  mutual_inductive_body * one_inductive_body -> types array 

(* [type_case_branches env (I,args) (p:A) c] computes useful types
   about the following Cases expression:
      <p>Cases (c :: (I args)) of b1..bn end
   It computes the type of every branch (pattern variables are
   introduced by products), the type for the whole expression, and
   the universe constraints generated.
 *)
val type_case_branches :
  env -> inductive * constr list -> unsafe_judgment -> constr
    -> types array * types * constraints

(* Check a [case_info] actually correspond to a Case expression on the
   given inductive type. *)
val check_case_info : env -> inductive -> case_info -> unit

(* Find the ultimate inductive in the [mind_equiv] chain *)

val scrape_mind : env -> mutual_inductive -> mutual_inductive

(*s Guard conditions for fix and cofix-points. *)
val check_fix : env -> fixpoint -> unit
val check_cofix : env -> cofixpoint -> unit