Might it be your naming? Try: procedure hello_world is
begin
put_line (“Hello from Ada”);
end Hello_world;
What is the *.abd suffex? Do you mean *.adb for a package body? Also the compiler is complaint that it cannot find the *.ads, the package specification file for (the package containing the procedure hello_world. I would say start putting everting into your own created packages, and use ‘with’ and ‘use’ as needed for basic Ada functionality. As in Pascal, you predefine things in a *.ads file and then put the corresponding bodies (the how) into a separate *.adb (package body) file.