PostGIS  2.5.0beta2dev-r@@SVN_REVISION@@
symdifference

symdifference - SELECT ST_SymDifference( 'POLYGON((0 0, 10 0, 10 10, 0 10, 0 0))', 'POLYGON((5 5, 15 5, 15 7, 5 7, 5 5))');