P.Mtext([],"(");P.Mo([],Netconversion.ustring_of_uchar `Enc_utf8 0xAC);
cexpr2pres a;P.Mtext([],")")])));
+(* inv *)
+Hashtbl.add C2P.symbol_table "inv" (unary
+ (fun a ~priority ~assoc ~tail attr sattr ->
+ P.Msup([],
+ P.Mrow([],[
+ P.Mtext([],"(");
+ cexpr2pres a;
+ P.Mtext([],")")]),
+ P.Mrow([],[
+ P.Mo([],"-");
+ P.Mn([],"1")]))));
+
+(* opp *)
+Hashtbl.add C2P.symbol_table "opp" (unary
+ (fun a ~priority ~assoc ~tail attr sattr ->
+ P.Mrow([],[
+ P.Mo([],"-");
+ P.Mtext([],"(");
+ cexpr2pres a;
+ P.Mtext([],")")])));
+
(* leq *)
Hashtbl.add C2P.symbol_table "leq" (binary
(fun a b ~priority ~assoc ~tail aattr sattr ->