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;