(* contexts *****************************************************************)

type svar_context = (MathQL.svar * MathQL.resource_set) list

type rvar_context = (MathQL.rvar * MathQL.resource) list

type group_context = (MathQL.rvar * MathQL.attribute_group) list

type vvar_context = (MathQL.vvar * MathQL.value) list


type context = {svars: svar_context;   (* contesto delle svar *)
                rvars: rvar_context;   (* contesto delle rvar *)
                groups: group_context; (* contesto dei gruppi *)
                vvars: vvar_context    (* contesto delle vvar introdotte con let-in *)
               }

let upd_svars c s = 
   {svars = s; rvars = c.rvars; groups = c.groups; vvars = c.vvars}

let upd_rvars c s = 
   {svars = c.svars; rvars = s; groups = c.groups; vvars = c.vvars}

let upd_groups c s = 
   {svars = c.svars; rvars = c.rvars; groups = s; vvars = c.vvars}

let upd_vvars c s = 
   {svars = c.svars; rvars = c.rvars; groups = c.groups; vvars = s}