This is a prototype of **JavaSketchpad**,
a World-Wide-Web component of *The
Geometer's Sketchpad.* Copyright ©1990-1998 by Key Curriculum
Press, Inc. All rights reserved. Portions of this work were funded by the
National Science Foundation (awards DMI 9561674 & 9623018).

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We want to see if the above frame is stable or not.
This can be found by looking at the associated bipartite graph which consists
of three row vertices corresponding to three rows and five column vertices
corresponding to five columns of the above frame, and an edge is conneted
between a row vertex and a column vertex if there is a diagonal supporter.
A frame is stable if and only if its cooresponding bipartite graph is connected.
For the above frame, the bipartite graph is not connected, so it is not
stable. Yonggu Kim.
Try to move the left one of two red
points.