return false;
//avoid two links being created from and to the same node
if ( activeStackPeek.hasHead() && dg.getTokenNode(activeStackPeek.getIndex()).getHead().getIndex() == inputPeek.getIndex() )
return false;
//enforce acyclicity constraint if present
if ( acyclicityConstraint && activeStackPeek.findComponent().getIndex() == inputPeek.findComponent().getIndex() )
return false;
}
if (trans == RIGHTARC) {
//enforce single-head constraint if present
if ( inputPeek.hasHead() && singleHeadConstraint )