with Ada.Strings.unbounded; use Ada.Strings.unbounded;
with Ada.Text_IO;       use Ada.Text_IO;

procedure str is

   P   : Unbounded_String := to_unbounded_string("T1/T2");
   R   : Unbounded_String := to_unbounded_string("");
   Pos : Natural;
begin

   Put_Line ("String P: " & to_string(P) & " " & Natural'Image (length(P)));

   Pos:=Index(P, "/", 1);
   R:=unbounded_slice(P,1,Pos-1);
   Put_Line ("String R: " & to_string(R) & " " & Natural'Image (length(R)));

   R:=unbounded_slice(P,Pos+1,Length(P));
   Put_Line ("String R: " & to_string(R) & " " & Natural'Image (length(R)));

end str;