+ let inf =
+ let inf' = remove node_to_be_deleted inf in
+ if List.length inf <> List.length inf' then
+ inf@@node'
+ else
+ inf
+ in
+ let sup =
+ let sup' = remove node_to_be_deleted sup in
+ if List.length sup <> List.length sup' then
+ sup@@node'
+ else
+ sup
+ in
+let set = nodes,inf,sup in
+(
+let _,inf,sup = set in
+if not (List.for_all (fun ((_,_,_,geq) as node) -> !geq = [] && let rec check_sups = function [] -> true | (_,_,leq,_) as node::tl -> if !leq = [] then List.exists (fun n -> n===node) sup && check_sups tl else check_sups (!leq@tl) in check_sups [node]) inf) then (ps_of_set ([],None,[]) set; assert false);
+if not (List.for_all (fun ((_,_,leq,_) as node) -> !leq = [] && let rec check_infs = function [] -> true | (_,_,_,geq) as node::tl -> if !geq = [] then List.exists (fun n -> n===node) inf && check_infs tl else check_infs (!geq@tl) in check_infs [node]) sup) then (ps_of_set ([],None,[]) set; assert false);
+);