Source file uState.ml
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open CErrors
open Util
open Names
open Univ
type universes_entry =
| Monomorphic_entry of Univ.ContextSet.t
| Polymorphic_entry of Univ.UContext.t
module UNameMap = Names.Id.Map
type uinfo = {
uname : Id.t option;
uloc : Loc.t option;
}
module UPairSet = UnivMinim.UPairSet
type t =
{ names : UnivNames.universe_binders * uinfo Level.Map.t; (** Printing/location information *)
local : ContextSet.t; (** The local graph of universes (variables and constraints) *)
seff_univs : Level.Set.t; (** Local universes used through private constants *)
univ_variables : UnivSubst.universe_opt_subst;
(** The local universes that are unification variables *)
univ_algebraic : Level.Set.t;
(** The subset of unification variables that can be instantiated with
algebraic universes as they appear in inferred types only. *)
universes : UGraph.t; (** The current graph extended with the local constraints *)
universes_lbound : UGraph.Bound.t; (** The lower bound on universes (e.g. Set or Prop) *)
initial_universes : UGraph.t; (** The graph at the creation of the evar_map *)
weak_constraints : UPairSet.t
}
let initial_sprop_cumulative = UGraph.set_cumulative_sprop true UGraph.initial_universes
let empty =
{ names = UNameMap.empty, Level.Map.empty;
local = ContextSet.empty;
seff_univs = Level.Set.empty;
univ_variables = Level.Map.empty;
univ_algebraic = Level.Set.empty;
universes = initial_sprop_cumulative;
universes_lbound = UGraph.Bound.Set;
initial_universes = initial_sprop_cumulative;
weak_constraints = UPairSet.empty; }
let elaboration_sprop_cumul =
Goptions.declare_bool_option_and_ref ~depr:false
~key:["Elaboration";"StrictProp";"Cumulativity"] ~value:true
let make ~lbound univs =
let univs = UGraph.set_cumulative_sprop (elaboration_sprop_cumul ()) univs in
{ empty with
universes = univs;
universes_lbound = lbound;
initial_universes = univs}
let is_empty uctx =
ContextSet.is_empty uctx.local &&
Level.Map.is_empty uctx.univ_variables
let uname_union s t =
if s == t then s
else
UNameMap.merge (fun k l r ->
match l, r with
| Some _, _ -> l
| _, _ -> r) s t
let union uctx uctx' =
if uctx == uctx' then uctx
else if is_empty uctx' then uctx
else
let local = ContextSet.union uctx.local uctx'.local in
let seff = Level.Set.union uctx.seff_univs uctx'.seff_univs in
let names = uname_union (fst uctx.names) (fst uctx'.names) in
let names_rev = Level.Map.lunion (snd uctx.names) (snd uctx'.names) in
let newus = Level.Set.diff (ContextSet.levels uctx'.local)
(ContextSet.levels uctx.local) in
let newus = Level.Set.diff newus (Level.Map.domain uctx.univ_variables) in
let weak = UPairSet.union uctx.weak_constraints uctx'.weak_constraints in
let declarenew g =
Level.Set.fold (fun u g -> UGraph.add_universe u ~lbound:uctx.universes_lbound ~strict:false g) newus g
in
{ names = (names, names_rev);
local = local;
seff_univs = seff;
univ_variables =
Level.Map.subst_union uctx.univ_variables uctx'.univ_variables;
univ_algebraic =
Level.Set.union uctx.univ_algebraic uctx'.univ_algebraic;
initial_universes = declarenew uctx.initial_universes;
universes =
(if local == uctx.local then uctx.universes
else
let cstrsr = ContextSet.constraints uctx'.local in
UGraph.merge_constraints cstrsr (declarenew uctx.universes));
universes_lbound = uctx.universes_lbound;
weak_constraints = weak}
let context_set uctx = uctx.local
let constraints uctx = snd uctx.local
let compute_instance_binders rbinders inst =
let map lvl =
try Name (Option.get (Level.Map.find lvl rbinders).uname)
with Option.IsNone | Not_found -> Anonymous
in
Array.map map (Instance.to_array inst)
let context uctx =
let (_, rbinders) = uctx.names in
ContextSet.to_context (compute_instance_binders rbinders) uctx.local
type named_universes_entry = universes_entry * UnivNames.universe_binders
let univ_entry ~poly uctx =
let (binders, _) = uctx.names in
let entry =
if poly then Polymorphic_entry (context uctx)
else Monomorphic_entry (context_set uctx) in
entry, binders
let of_context_set local = { empty with local }
type universe_opt_subst = UnivSubst.universe_opt_subst
let subst uctx = uctx.univ_variables
let nf_universes uctx c =
UnivSubst.nf_evars_and_universes_opt_subst (fun _ -> None) (subst uctx) c
let ugraph uctx = uctx.universes
let initial_graph uctx = uctx.initial_universes
let algebraics uctx = uctx.univ_algebraic
let add_names ?loc s l (names, names_rev) =
if UNameMap.mem s names
then user_err ?loc
Pp.(str "Universe " ++ Names.Id.print s ++ str" already bound.");
(UNameMap.add s l names, Level.Map.add l { uname = Some s; uloc = loc } names_rev)
let add_loc l loc (names, names_rev) =
match loc with
| None -> (names, names_rev)
| Some _ -> (names, Level.Map.add l { uname = None; uloc = loc } names_rev)
let of_binders names =
let rev_map =
UNameMap.fold (fun id l rmap ->
Level.Map.add l { uname = Some id; uloc = None } rmap)
names Level.Map.empty
in
{ empty with names = (names, rev_map) }
let universe_of_name uctx s =
UNameMap.find s (fst uctx.names)
let universe_binders uctx =
let named, _ = uctx.names in
named
let instantiate_variable l b v =
try v := Level.Map.set l (Some b) !v
with Not_found -> assert false
exception UniversesDiffer
let drop_weak_constraints =
Goptions.declare_bool_option_and_ref
~depr:false
~key:["Cumulativity";"Weak";"Constraints"]
~value:false
let process_universe_constraints uctx cstrs =
let open UnivSubst in
let open UnivProblem in
let univs = uctx.universes in
let vars = ref uctx.univ_variables in
let weak = ref uctx.weak_constraints in
let normalize u = normalize_univ_variable_opt_subst !vars u in
let nf_constraint = function
| ULub (u, v) -> ULub (level_subst_of normalize u, level_subst_of normalize v)
| UWeak (u, v) -> UWeak (level_subst_of normalize u, level_subst_of normalize v)
| UEq (u, v) -> UEq (subst_univs_universe normalize u, subst_univs_universe normalize v)
| ULe (u, v) -> ULe (subst_univs_universe normalize u, subst_univs_universe normalize v)
in
let is_local l = Level.Map.mem l !vars in
let varinfo x =
match Universe.level x with
| None -> Inl x
| Some l -> Inr l
in
let equalize_variables fo l l' r r' local =
let () =
if is_local l' then
instantiate_variable l' r vars
else if is_local r' then
instantiate_variable r' l vars
else if not (UGraph.check_eq_level univs l' r') then
if Level.is_small l' || Level.is_small r' then
raise (UniverseInconsistency (Eq, l, r, None))
else if fo then
raise UniversesDiffer
in
enforce_eq_level l' r' local
in
let equalize_universes l r local = match varinfo l, varinfo r with
| Inr l', Inr r' -> equalize_variables false l l' r r' local
| Inr l, Inl r | Inl r, Inr l ->
let alg = Level.Set.mem l uctx.univ_algebraic in
let inst = univ_level_rem l r r in
if alg && not (Level.Set.mem l (Universe.levels inst)) then
(instantiate_variable l inst vars; local)
else
let lu = Universe.make l in
if univ_level_mem l r then
enforce_leq inst lu local
else raise (UniverseInconsistency (Eq, lu, r, None))
| Inl _, Inl _ ->
if UGraph.check_eq univs l r then local
else raise (UniverseInconsistency (Eq, l, r, None))
in
let unify_universes cst local =
let cst = nf_constraint cst in
if UnivProblem.is_trivial cst then local
else
match cst with
| ULe (l, r) ->
begin match Univ.Universe.level r with
| None ->
if UGraph.check_leq univs l r then local
else user_err Pp.(str "Algebraic universe on the right")
| Some r' ->
if Level.is_small r' then
if not (Universe.is_levels l)
then
raise (UniverseInconsistency (Le, l, r, None))
else
if UGraph.check_leq univs l r then match Univ.Universe.level l with
| Some l ->
Univ.Constraints.add (l, Le, r') local
| None -> local
else
let levels = Universe.levels l in
let fold l' local =
let l = Universe.make l' in
if Level.is_small l' || is_local l' then
equalize_variables false l l' r r' local
else raise (UniverseInconsistency (Le, l, r, None))
in
Level.Set.fold fold levels local
else
match Univ.Universe.level l with
| Some l ->
Univ.Constraints.add (l, Le, r') local
| None ->
enforce_leq l r local
end
| ULub (l, r) ->
equalize_variables true (Universe.make l) l (Universe.make r) r local
| UWeak (l, r) ->
if not (drop_weak_constraints ()) then weak := UPairSet.add (l,r) !weak; local
| UEq (l, r) -> equalize_universes l r local
in
let unify_universes cst local =
if not (UGraph.type_in_type univs) then unify_universes cst local
else try unify_universes cst local with UniverseInconsistency _ -> local
in
let local =
UnivProblem.Set.fold unify_universes cstrs Constraints.empty
in
!vars, !weak, local
let add_constraints uctx cstrs =
let univs, old_cstrs = uctx.local in
let cstrs' = Constraints.fold (fun (l,d,r) acc ->
let l = Universe.make l and r = Universe.make r in
let cstr' = let open UnivProblem in
match d with
| Lt ->
ULe (Universe.super l, r)
| Le -> ULe (l, r)
| Eq -> UEq (l, r)
in UnivProblem.Set.add cstr' acc)
cstrs UnivProblem.Set.empty
in
let vars, weak, cstrs' = process_universe_constraints uctx cstrs' in
{ uctx with
local = (univs, Constraints.union old_cstrs cstrs');
univ_variables = vars;
universes = UGraph.merge_constraints cstrs' uctx.universes;
weak_constraints = weak; }
let add_universe_constraints uctx cstrs =
let univs, local = uctx.local in
let vars, weak, local' = process_universe_constraints uctx cstrs in
{ uctx with
local = (univs, Constraints.union local local');
univ_variables = vars;
universes = UGraph.merge_constraints local' uctx.universes;
weak_constraints = weak; }
let constrain_variables diff uctx =
let univs, local = uctx.local in
let univs, vars, local =
Level.Set.fold
(fun l (univs, vars, cstrs) ->
try
match Level.Map.find l vars with
| Some u ->
(Level.Set.add l univs,
Level.Map.remove l vars,
Constraints.add (l, Eq, Option.get (Universe.level u)) cstrs)
| None -> (univs, vars, cstrs)
with Not_found | Option.IsNone -> (univs, vars, cstrs))
diff (univs, uctx.univ_variables, local)
in
{ uctx with local = (univs, local); univ_variables = vars }
let id_of_level uctx l =
try Some (Option.get (Level.Map.find l (snd uctx.names)).uname)
with Not_found | Option.IsNone ->
None
let qualid_of_level uctx l =
let map, map_rev = uctx.names in
try Some (Libnames.qualid_of_ident (Option.get (Level.Map.find l map_rev).uname))
with Not_found | Option.IsNone ->
UnivNames.qualid_of_level map l
let pr_uctx_level uctx l =
match qualid_of_level uctx l with
| Some qid -> Libnames.pr_qualid qid
| None -> Level.pr l
type ('a, 'b) gen_universe_decl = {
univdecl_instance : 'a;
univdecl_extensible_instance : bool;
univdecl_constraints : 'b;
univdecl_extensible_constraints : bool }
type universe_decl =
(lident list, Constraints.t) gen_universe_decl
let default_univ_decl =
{ univdecl_instance = [];
univdecl_extensible_instance = true;
univdecl_constraints = Constraints.empty;
univdecl_extensible_constraints = true }
let pr_error_unbound_universes left uctx =
let open Pp in
let n = Level.Set.cardinal left in
let prlev u =
let info = Level.Map.find_opt u (snd uctx.names) in
h (pr_uctx_level uctx u ++ (match info with
| None | Some {uloc=None} -> mt ()
| Some {uloc=Some loc} -> spc() ++ str"(" ++ Loc.pr loc ++ str")"))
in
(hv 0
(str (CString.plural n "Universe") ++ spc () ++
(prlist_with_sep spc prlev (Level.Set.elements left)) ++
spc () ++ str (CString.conjugate_verb_to_be n) ++ str" unbound."))
exception UnboundUnivs of Level.Set.t * t
let error_unbound_universes left uctx = raise (UnboundUnivs (left,uctx))
let _ = CErrors.register_handler (function
| UnboundUnivs (left,uctx) -> Some (pr_error_unbound_universes left uctx)
| _ -> None)
let universe_context ~names ~extensible uctx =
let levels = ContextSet.levels uctx.local in
let newinst, left =
List.fold_right
(fun { CAst.loc; v = id } (newinst, acc) ->
let l =
try universe_of_name uctx id
with Not_found -> assert false
in (l :: newinst, Level.Set.remove l acc))
names ([], levels)
in
if not extensible && not (Level.Set.is_empty left)
then error_unbound_universes left uctx
else
let left = ContextSet.sort_levels (Array.of_list (Level.Set.elements left)) in
let inst = Array.append (Array.of_list newinst) left in
let inst = Instance.of_array inst in
(inst, ContextSet.constraints uctx.local)
let check_universe_context_set ~names ~extensible uctx =
if extensible then ()
else
let left = List.fold_left (fun left { CAst.loc; v = id } ->
let l =
try universe_of_name uctx id
with Not_found -> assert false
in Level.Set.remove l left)
(ContextSet.levels uctx.local) names
in
if not (Level.Set.is_empty left)
then error_unbound_universes left uctx
let check_implication uctx cstrs cstrs' =
let gr = initial_graph uctx in
let grext = UGraph.merge_constraints cstrs gr in
let cstrs' = Constraints.filter (fun c -> not (UGraph.check_constraint grext c)) cstrs' in
if Constraints.is_empty cstrs' then ()
else CErrors.user_err
Pp.(str "Universe constraints are not implied by the ones declared: " ++
pr_constraints (pr_uctx_level uctx) cstrs')
let check_mono_univ_decl uctx decl =
let () =
let names = decl.univdecl_instance in
let extensible = decl.univdecl_extensible_instance in
check_universe_context_set ~names ~extensible uctx
in
if not decl.univdecl_extensible_constraints then
check_implication uctx
decl.univdecl_constraints
(ContextSet.constraints uctx.local);
uctx.local
let check_univ_decl ~poly uctx decl =
if not decl.univdecl_extensible_constraints then
check_implication uctx
decl.univdecl_constraints
(ContextSet.constraints uctx.local);
let names = decl.univdecl_instance in
let extensible = decl.univdecl_extensible_instance in
let (binders, rbinders) = uctx.names in
if poly then
let inst, csts = universe_context ~names ~extensible uctx in
let nas = compute_instance_binders rbinders inst in
let uctx = UContext.make nas (inst, csts) in
Polymorphic_entry uctx, binders
else
let () = check_universe_context_set ~names ~extensible uctx in
Monomorphic_entry uctx.local, binders
let is_bound l lbound = match lbound with
| UGraph.Bound.Prop -> Level.is_prop l
| UGraph.Bound.Set -> Level.is_set l
let restrict_universe_context ~lbound (univs, csts) keep =
let removed = Level.Set.diff univs keep in
if Level.Set.is_empty removed then univs, csts
else
let allunivs = Constraints.fold (fun (u,_,v) all -> Level.Set.add u (Level.Set.add v all)) csts univs in
let g = UGraph.initial_universes in
let g = Level.Set.fold (fun v g -> if Level.is_small v then g else
UGraph.add_universe v ~lbound ~strict:false g) allunivs g in
let g = UGraph.merge_constraints csts g in
let allkept = Level.Set.union (UGraph.domain UGraph.initial_universes) (Level.Set.diff allunivs removed) in
let csts = UGraph.constraints_for ~kept:allkept g in
let csts = Constraints.filter (fun (l,d,r) ->
not ((is_bound l lbound && d == Le) || (Level.is_prop l && d == Lt && Level.is_set r))) csts in
(Level.Set.inter univs keep, csts)
let restrict uctx vars =
let vars = Level.Set.union vars uctx.seff_univs in
let vars = Names.Id.Map.fold (fun na l vars -> Level.Set.add l vars)
(fst uctx.names) vars
in
let uctx' = restrict_universe_context ~lbound:uctx.universes_lbound uctx.local vars in
{ uctx with local = uctx' }
type rigid =
| UnivRigid
| UnivFlexible of bool (** Is substitution by an algebraic ok? *)
let univ_rigid = UnivRigid
let univ_flexible = UnivFlexible false
let univ_flexible_alg = UnivFlexible true
(** ~sideff indicates that it is ok to redeclare a universe.
~extend also merges the universe context in the local constraint structures
and not only in the graph. This depends if the
context we merge comes from a side effect that is already inlined
or defined separately. In the later case, there is no extension,
see [emit_side_effects] for example. *)
let merge ?loc ~sideff rigid uctx uctx' =
let levels = ContextSet.levels uctx' in
let uctx =
match rigid with
| UnivRigid -> uctx
| UnivFlexible b ->
let fold u accu =
if Level.Map.mem u accu then accu
else Level.Map.add u None accu
in
let uvars' = Level.Set.fold fold levels uctx.univ_variables in
if b then
{ uctx with univ_variables = uvars';
univ_algebraic = Level.Set.union uctx.univ_algebraic levels }
else { uctx with univ_variables = uvars' }
in
let local = ContextSet.append uctx' uctx.local in
let declare g =
Level.Set.fold (fun u g ->
try UGraph.add_universe ~lbound:uctx.universes_lbound ~strict:false u g
with UGraph.AlreadyDeclared when sideff -> g)
levels g
in
let names =
let fold u accu =
let modify _ info = match info.uloc with
| None -> { info with uloc = loc }
| Some _ -> info
in
try Level.Map.modify u modify accu
with Not_found -> Level.Map.add u { uname = None; uloc = loc } accu
in
(fst uctx.names, Level.Set.fold fold levels (snd uctx.names))
in
let initial = declare uctx.initial_universes in
let univs = declare uctx.universes in
let universes = UGraph.merge_constraints (ContextSet.constraints uctx') univs in
{ uctx with names; local; universes;
initial_universes = initial }
let merge_subst uctx s =
{ uctx with univ_variables = Level.Map.subst_union uctx.univ_variables s }
let demote_seff_univs univs uctx =
let seff = Level.Set.union uctx.seff_univs univs in
{ uctx with seff_univs = seff }
let demote_global_univs env uctx =
let env_ugraph = Environ.universes env in
let global_univs = UGraph.domain env_ugraph in
let global_constraints, _ = UGraph.constraints_of_universes env_ugraph in
let promoted_uctx =
ContextSet.(of_set global_univs |> add_constraints global_constraints) in
{ uctx with local = ContextSet.diff uctx.local promoted_uctx }
let merge_seff uctx uctx' =
let levels = ContextSet.levels uctx' in
let declare g =
Level.Set.fold (fun u g ->
try UGraph.add_universe ~lbound:uctx.universes_lbound ~strict:false u g
with UGraph.AlreadyDeclared -> g)
levels g
in
let initial_universes = declare uctx.initial_universes in
let univs = declare uctx.universes in
let universes = UGraph.merge_constraints (ContextSet.constraints uctx') univs in
{ uctx with universes; initial_universes }
let emit_side_effects eff u =
let uctx = Safe_typing.universes_of_private eff in
let u = demote_seff_univs (fst uctx) u in
merge_seff u uctx
let update_sigma_univs uctx ugraph =
let univs = UGraph.set_cumulative_sprop (elaboration_sprop_cumul()) ugraph in
let eunivs =
{ uctx with
initial_universes = univs;
universes = univs }
in
merge_seff eunivs eunivs.local
let add_universe ?loc name strict lbound uctx u =
let initial_universes = UGraph.add_universe ~lbound ~strict u uctx.initial_universes in
let universes = UGraph.add_universe ~lbound ~strict u uctx.universes in
let local = ContextSet.add_universe u uctx.local in
let names =
match name with
| Some n -> add_names ?loc n u uctx.names
| None -> add_loc u loc uctx.names
in
{ uctx with names; local; initial_universes; universes }
let new_univ_variable ?loc rigid name uctx =
let u = UnivGen.fresh_level () in
let uctx =
match rigid with
| UnivRigid -> uctx
| UnivFlexible allow_alg ->
let univ_variables = Level.Map.add u None uctx.univ_variables in
if allow_alg
then
let univ_algebraic = Level.Set.add u uctx.univ_algebraic in
{ uctx with univ_variables; univ_algebraic }
else
{ uctx with univ_variables }
in
let uctx = add_universe ?loc name false uctx.universes_lbound uctx u in
uctx, u
let add_global_univ uctx u = add_universe None true UGraph.Bound.Set uctx u
let make_with_initial_binders ~lbound univs us =
let uctx = make ~lbound univs in
List.fold_left
(fun uctx { CAst.loc; v = id } ->
fst (new_univ_variable ?loc univ_rigid (Some id) uctx))
uctx us
let from_env ?(binders=[]) env =
make_with_initial_binders ~lbound:(Environ.universes_lbound env) (Environ.universes env) binders
let make_flexible_variable uctx ~algebraic u =
let {local = cstrs; univ_variables = uvars;
univ_algebraic = avars; universes=g; } = uctx in
assert (try Level.Map.find u uvars == None with Not_found -> true);
match UGraph.choose (fun v -> not (Level.equal u v) && (algebraic || not (Level.Set.mem v avars))) g u with
| Some v ->
let uvars' = Level.Map.add u (Some (Universe.make v)) uvars in
{ uctx with univ_variables = uvars'; }
| None ->
let uvars' = Level.Map.add u None uvars in
let avars' =
if algebraic then
let uu = Universe.make u in
let substu_not_alg u' v =
Option.cata (fun vu -> Universe.equal uu vu && not (Level.Set.mem u' avars)) false v
in
let has_upper_constraint () =
Constraints.exists
(fun (l,d,r) -> d == Lt && Level.equal l u)
(ContextSet.constraints cstrs)
in
if not (Level.Map.exists substu_not_alg uvars || has_upper_constraint ())
then Level.Set.add u avars else avars
else avars
in
{ uctx with univ_variables = uvars'; univ_algebraic = avars' }
let make_nonalgebraic_variable uctx u =
{ uctx with univ_algebraic = Level.Set.remove u uctx.univ_algebraic }
let make_flexible_nonalgebraic uctx =
{ uctx with univ_algebraic = Level.Set.empty }
let is_sort_variable uctx s =
match s with
| Sorts.Type u ->
(match universe_level u with
| Some l as x ->
if Level.Set.mem l (ContextSet.levels uctx.local) then x
else None
| None -> None)
| _ -> None
let subst_univs_context_with_def def usubst (uctx, cst) =
(Level.Set.diff uctx def, UnivSubst.subst_univs_constraints usubst cst)
let is_trivial_leq (l,d,r) =
Level.is_prop l && (d == Le || d == Lt) && Level.is_set r
let translate_cstr (l,d,r as cstr) =
if Level.equal Level.prop l && d == Lt && not (Level.equal Level.set r) then
(Level.set, d, r)
else cstr
let refresh_constraints univs (ctx, cstrs) =
let cstrs', univs' =
Constraints.fold (fun c (cstrs', univs as acc) ->
let c = translate_cstr c in
if is_trivial_leq c then acc
else (Constraints.add c cstrs', UGraph.enforce_constraint c univs))
cstrs (Constraints.empty, univs)
in ((ctx, cstrs'), univs')
let normalize_variables uctx =
let normalized_variables, def, subst =
UnivSubst.normalize_univ_variables uctx.univ_variables
in
let uctx_local = subst_univs_context_with_def def (make_subst subst) uctx.local in
let uctx_local', univs = refresh_constraints uctx.initial_universes uctx_local in
{ uctx with
local = uctx_local';
univ_variables = normalized_variables;
universes = univs }
let abstract_undefined_variables uctx =
let vars' =
Level.Map.fold (fun u v acc ->
if v == None then Level.Set.remove u acc
else acc)
uctx.univ_variables uctx.univ_algebraic
in { uctx with local = ContextSet.empty;
univ_algebraic = vars' }
let fix_undefined_variables uctx =
let algs', vars' =
Level.Map.fold (fun u v (algs, vars as acc) ->
if v == None then (Level.Set.remove u algs, Level.Map.remove u vars)
else acc)
uctx.univ_variables
(uctx.univ_algebraic, uctx.univ_variables)
in
{ uctx with univ_variables = vars';
univ_algebraic = algs' }
let minimize uctx =
let open UnivMinim in
let lbound = uctx.universes_lbound in
let ((vars',algs'), us') =
normalize_context_set ~lbound uctx.universes uctx.local uctx.univ_variables
uctx.univ_algebraic uctx.weak_constraints
in
if ContextSet.equal us' uctx.local then uctx
else
let us', universes =
refresh_constraints uctx.initial_universes us'
in
{ names = uctx.names;
local = us';
seff_univs = uctx.seff_univs;
univ_variables = vars';
univ_algebraic = algs';
universes = universes;
universes_lbound = lbound;
initial_universes = uctx.initial_universes;
weak_constraints = UPairSet.empty; }
let pr_weak prl {weak_constraints=weak} =
let open Pp in
prlist_with_sep fnl (fun (u,v) -> prl u ++ str " ~ " ++ prl v) (UPairSet.elements weak)
let pr_universe_body = function
| None -> Pp.mt ()
| Some x -> Pp.(str " := " ++ Univ.Universe.pr x)
let pr_universe_opt_subst = Univ.Level.Map.pr pr_universe_body