premise: Nothing in computer sense is called by its full name . 
hypothesis: After it has been installed , the DOS , as it is called ( once identified , nothing in computerese is ever called by its full name a Personal Computer becomes a PC ; a Disk Operating System becomes a DOS ; if it is made by a company called MicroSoft , it is called MS/DOS ) , performs certain functions , though rarely any that anyone but a computer specialist would want to perform .