Added an example of a super simple cycle.

Note: Might not want to include this without a disclaimer for people that they should not create cyclic patterns.

:-)

index.html

@@ -581,6 +581,7 @@ <h1>Blocks:</h1>
 			// probably will change keycode. 
 			// Run topological sort. 
 			if (!checkGlobalCellCorrectness()) console.log("Warning: Topological sort shows a cycle in yarn directions!");
+			else console.log("Topological sort passes!");
 		}else if (evt.code == 'ArrowUp') {
 			prevTemplate();
 			requestRedraw();

simple-cycle.body

@@ -0,0 +1 @@
+[{"template":"yarn-next-row x x x x -y1 +y1 x","vertices":[[1.781298682084002,-0.6721302882101465,-0.444],[1.781298682084002,-0.672130288210147,0.44400000000000045],[1.781298682084001,1.3278697117898544,-0.444],[1.781298682084001,1.327869711789854,0.44400000000000045],[2.3812986820840023,-0.6721302882101465,-0.44400000000000023],[2.3812986820840023,-0.672130288210147,0.44400000000000023],[2.381298682084002,0.3278697117898539,-0.44400000000000023],[2.381298682084002,0.32786971178985347,0.44400000000000023],[2.3812986820840014,1.3278697117898544,-0.44400000000000023],[2.3812986820840014,1.327869711789854,0.44400000000000023]],"connections":[null,null,null,null,{"cell":1,"face":3},{"cell":1,"face":2},null]},{"template":"yarn-next-row x x -y1 +y1 x x x","vertices":[[3.331797213710457,-0.5480778954542336,-0.444],[3.331797213710457,-0.5480778954542336,0.444],[3.331797213710457,0.4519221045457664,-0.444],[3.331797213710457,0.4519221045457664,0.444],[3.331797213710457,1.4519221045457664,-0.444],[3.331797213710457,1.4519221045457664,0.444],[3.9317972137104564,-0.5480778954542336,-0.444],[3.9317972137104564,-0.5480778954542336,0.444],[3.9317972137104564,1.4519221045457664,-0.444],[3.9317972137104564,1.4519221045457664,0.444]],"connections":[null,null,{"cell":0,"face":5},{"cell":0,"face":4},null,null,null]}]