Remind John by 3pm that his meeting with Frank is at 4pm.
[IN:CREATE_REMINDER Remind [SL:PERSON_REMINDED John ] [SL:DATE_TIME by 3 pm ] that [SL:TODO [IN:GET_TODO [SL:TODO his meeting ] with [SL:ATTENDEE Frank ] is [SL:DATE_TIME at 4 pm ] ] ] . ]