app.adb

pragma License (Gpl);
pragma Ada_2012;

with Ada.Text_IO;

procedure App is
   package I_IO is new Ada.Text_IO.Integer_IO (Integer);

   function Add (X : in Integer; Y : in Integer) return Integer
   with
      Pre => X > 5,
      Post => Add'Result > 5;

   A    : Integer;
   B    : Integer;

   function Add (X : in Integer; Y : in Integer) return Integer
   is
   begin
      return X + Y;
   end Add;

begin
   A := 1;
   B := 1;
   Ada.Text_IO.Put ("Output: ");
   I_IO.Put (Add (A, B));
   return;
end App;

app.gpr

project App is
   for Source_Dirs use (".");
   for Main use ("app.adb");

   package Builder is
      for Default_Switches ("ada") use ("-gnatVa", "-gnatwa", "-gnaty", "-g");
   end Builder;

   package Compiler is
      for Default_Switches ("ada") use ("-gnatVa", "-gnatwa", "-gnaty", "-g");
   end Compiler;

end App;