Added theorems setsum_reindex_nonzero, setsum_mono_zero_left, setsum_mono_zero_right, setsum_mono_zero_cong_left, setsum_mono_zero_cong_right, setsum_delta, strong_setprod_reindex_cong, setprod_delta
/***************************************************************************
Title: GraphBrowser/DummyVertex.java
ID: $Id$
Author: Stefan Berghofer, TU Muenchen
Copyright 1997 TU Muenchen
This class represents a dummy vertex, which is used to simplify the
layout algorithm.
***************************************************************************/
package GraphBrowser;
import java.awt.*;
class DummyVertex extends Vertex {
public boolean isDummy() {return true;}
public Object clone() {
Vertex ve=new DummyVertex();
ve.setX(getX());ve.setY(getY());
return ve;
}
public int leftX() { return getX(); }
public int rightX() { return getX(); }
public void draw(Graphics g) {}
}