* http://cs.unibo.it/helm/.
*)
+(*
let reduction_tac ~reduction ~status:(proof,goal) =
let curi,metasenv,pbo,pty = proof in
let metano,context,ty = List.find (function (m,_,_) -> m=goal) metasenv in
in
(curi,new_metasenv,pbo,pty), [metano]
;;
+*)
+
+(* The default of term is the thesis of the goal to be prooved *)
+let reduction_tac ~also_in_hypotheses ~reduction ~term ~status:(proof,goal) =
+ let curi,metasenv,pbo,pty = proof in
+ let metano,context,ty = List.find (function (m,_,_) -> m=goal) metasenv in
+ let term =
+ match term with None -> ty | Some t -> t
+ in
+ (* We don't know if [term] is a subterm of [ty] or a subterm of *)
+ (* the type of one metavariable. So we replace it everywhere. *)
+ (*CSC: Il vero problema e' che non sapendo dove sia il term non *)
+ (*CSC: sappiamo neppure quale sia il suo contesto!!!! Insomma, *)
+ (*CSC: e' meglio prima cercare il termine e scoprirne il *)
+ (*CSC: contesto, poi ridurre e infine rimpiazzare. *)
+ let replace context where=
+(*CSC: Per il momento se la riduzione fallisce significa solamente che *)
+(*CSC: siamo nel contesto errato. Metto il try, ma che schifo!!!! *)
+(*CSC: Anche perche' cosi' catturo anche quelle del replace che non dovrei *)
+ try
+ let term' = reduction context term in
+ ProofEngineReduction.replace ~equality:(==) ~what:term ~with_what:term'
+ ~where:where
+ with
+ _ -> where
+ in
+ let ty' = replace context ty in
+ let context' =
+ if also_in_hypotheses then
+ List.fold_right
+ (fun entry context ->
+ match entry with
+ Some (name,Cic.Def t) ->
+ (Some (name,Cic.Def (replace context t)))::context
+ | Some (name,Cic.Decl t) ->
+ (Some (name,Cic.Decl (replace context t)))::context
+ | None -> None::context
+ ) context []
+ else
+ context
+ in
+ let metasenv' =
+ List.map
+ (function
+ (n,_,_) when n = metano -> (metano,context',ty')
+ | _ as t -> t
+ ) metasenv
+ in
+ (curi,metasenv',pbo,pty), [metano]
+;;
let simpl_tac = reduction_tac ~reduction:ProofEngineReduction.simpl ;;
let reduce_tac = reduction_tac ~reduction:ProofEngineReduction.reduce ;;