* http://cs.unibo.it/helm/.
*)
-exception UnificationFailed
-exception Free
-exception OccurCheck
-
-(* The entry (i,t) in a substitution means that *)
-(* (META i) have been instantiated with t. *)
-type substitution = (int * Cic.term) list
+exception UnificationFailure of string;;
+exception Uncertain of string;;
+exception AssertFailure of string;;
(* fo_unif metasenv context t1 t2 *)
(* unifies [t1] and [t2] in a context [context]. *)
(* Only the metavariables declared in [metasenv] *)
(* can be used in [t1] and [t2]. *)
+(* The returned substitution can be directly *)
+(* withouth first unwinding it. *)
val fo_unif :
- (int * Cic.term) list -> Cic.context -> Cic.term -> Cic.term -> substitution
+ Cic.metasenv -> Cic.context -> Cic.term -> Cic.term ->
+ CicMetaSubst.substitution * Cic.metasenv
-(* apply_subst subst t *)
-(* applies the substitution [sust] to [t] *)
-val apply_subst : substitution -> Cic.term -> Cic.term
+(* fo_unif_subst metasenv subst context t1 t2 *)
+(* unifies [t1] and [t2] in a context [context] *)
+(* and with [subst] as the current substitution *)
+(* (i.e. unifies ([subst] [t1]) and *)
+(* ([subst] [t2]) in a context *)
+(* ([subst] [context]) using the metasenv *)
+(* ([subst] [metasenv]) *)
+(* Only the metavariables declared in [metasenv] *)
+(* can be used in [t1] and [t2]. *)
+(* [subst] and the substitution returned are not *)
+(* unwinded. *)
+(*CSC: fare un tipo unione Unwinded o ToUnwind e fare gestire la
+ cosa all'apply_subst!!!*)
+val fo_unif_subst :
+ CicMetaSubst.substitution ->
+ Cic.context -> Cic.metasenv -> Cic.term -> Cic.term ->
+ CicMetaSubst.substitution * Cic.metasenv
-(* apply_subst_reducing subst (Some (mtr,reductions_no)) t *)
-(* performs as (apply_subst subst t) until it finds an application of *)
-(* (META [mtr]) that, once unwinding is performed, creates a new *)
-(* beta-redex; in this case up to [reductions_no] consecutive *)
-(* beta-reductions are performed. *)
-(* Hint: this function is usually called when [reductions_no] *)
-(* eta-expansions have been performed and the head of the new *)
-(* application has been unified with (META [meta_to_reduce]): *)
-(* during the unwinding the eta-expansions are undone. *)
-val apply_subst_reducing :
- substitution -> (int * int) option -> Cic.term -> Cic.term