: ON ERROR GOTO 0, Turns of the error trap, and restores normal error processing.
==== <code>ON variable GOTO ln x1, x2, x3, x4, ...</code> ====
: In case of passing more choices ON variable GOTO ln x1, x2, x3, x4, ... points to a table with the jumping target.
==== <code>OPENIN "datafile"</code> ====