I placed a gosub within a gosub!

Just don't do @A GOSUB @A

Insert some spaces called "Colum" or "Indent" for easily view.Below: @MAIN FOR I=0 TO 50 GOSUB @P GOSUB @O GOSUB @L NEXT END @P PRINT "P" RETURN :

Yep, procedures that call other procedures is a very common thing in programming. Pretty much every large software product does it.