Remind David to leave by 5 pm for the concert, set up an alert 20 minutes before
[IN:CREATE_REMINDER Remind [SL:PERSON_REMINDED David ] to [SL:TODO [IN:GET_TODO [SL:TODO leave ] [SL:DATE_TIME by 5 pm ] [SL:TODO for the concert ] ] ] , set up an alert [SL:DATE_TIME 20 minutes before ] ]