@prefix math: <http://www.w3.org/2000/10/swap/math#>.
@prefix e: <http://eulersharp.sourceforge.net/2003/03swap/log-rules#>.
@prefix polygon: <http://josd.github.io/eye/reasoning/polygon#>.

((4 2) (6 2) (7 6) (4 6) (5 5) (5 3) (4 2)) polygon:area 7 .

