Rob needs to leave at 4:30pm today.  Remind him 15 minutes prior.
[IN:CREATE_REMINDER Rob needs to [SL:TODO [IN:GET_TODO [SL:TODO leave ] [SL:DATE_TIME at 4 : 30 pm today ] ] ] . Remind [SL:PERSON_REMINDED him ] [SL:DATE_TIME 15 minutes prior ] . ]