an> waitforthread (athread: tmsethread);
        <span style="color:navy"><b>FUNCTION</b></span> semwait (var sem: semty;  timeoutusec: integer): syserrorty;
        <span style="color:navy"><b>PROCEDURE</b></span> wakeupmainthread;
        <span style="color:navy"><b>PROCEDURE</b></span> langchanged; <span style="color:teal"><b>VIRTUAL</b></span>;
        <span style="color:navy"><b>PROCEDURE</b></span> beginwait (const aprocessmessages: boolean = false); <span style="color:teal"><b>VIRTUAL</b></span>;
   