|| tail instanceof Relation) {
String moml = "<deleteRelation name=\""
+ relation.getName() + "\"/>";
MoMLChangeRequest request = new MoMLChangeRequest(
this, relation.getContainer(), moml);
request.execute();
if (tail instanceof Relation) {
moml = _getLinkMoML(head, (Relation) tail);
request = new MoMLChangeRequest(this, tail
.getContainer(), moml);