func (d *ltDom) eval(v vName) vName {
	if d.ancestor[v] == -1 {
		return v
	}
	d.compress(v)
	return d.labels[v]
}
func (d *ltDom) eval(v vName) vName {
	if d.ancestor[v] == -1 {
		return v
	}
	d.compress(v)
	return d.labels[v]
}
func ( d * ltDom ) eval ( v vName ) vName { if d . ancestor [ v ] == - 1 { return v } d . compress ( v ) return d . labels [ v ] }
// eval is EVAL from the papers.
eval is EVAL from the papers .