Grm_def 4grm "Sven Wachsmuth & Gernot A. Fink" - "ESMERALDA-Manual"

This is an example grammar describing a time constituent:
$TIME	      : $DAY $TIME_CIRCA $TIME_PRECISE ;
$DAY	      : today ;
$TIME_CIRCA   : in the morning | ;
$TIME_PRECISE : at $TIME_HOUR oclock | at $TIME_HOUR point $TIME_MIN | ;
$TIME_HOUR    : one | two | three ;
$TIME_MIN     : zero | fifteen | thirty ;
$$S	      : $TIME ;

Some word sequences defined by the grammar are:

today in the morning
today in the morning at three oclock
today at one point thirty
today