Remind Mom to leave at 10; alert them 20 minutes before.
[IN:CREATE_REMINDER Remind [SL:PERSON_REMINDED [IN:GET_CONTACT [SL:TYPE_RELATION Mom ] ] ] to [SL:TODO [IN:GET_TODO [SL:TODO leave ] [SL:DATE_TIME at 10 ] ] ] ; alert them [SL:DATE_TIME 20 minutes before ] . ]