// straightness constraints

constraint V16.CB L20.CB	14 14.6 16
constraint V216.CB L220.CB	14 14.6 16

// try antiparallel  	vvvrl
//			lrvvv
constraint V16.CB L220.CB	4 4.7 6
constraint V17.CB R219.CB	4 4.7 6
constraint V18.CB V218.CB	4 4.7 6
constraint R19.CB V217.CB	4 4.7 6
constraint L20.CB V216.CB	4 4.7 6