come about vs come of

To come to pass; to develop; to occur; to take place; to happen; to exist. 

To tack; to change tack; to maneuver the bow of a sailing vessel across the wind so that the wind changes from one side of the vessel to the other; to position a boat with respect to the wind after tacking. See also come to. 

To change; to come round. 

To result from.