RE: [math-fun] Geometry/topology question about planar graphs

-----Original Message----- From: John Conway [mailto:conway@Math.Princeton.EDU] e. However, the "Carpenter's Ruler" problem (are the plane embeddings of a hinged ruler interconvertible in this way, keeping the segment-lengths fixed) is quite difficult - indeed I think it's still unsolved,

This was finally solved, in the affirmative, by Erik Demaine, Robert Connelly, and Guenter Rote. http://theory.lcs.mit.edu/~edemaine/papers/Linkage/

and the corresponding assertion for arbitary graphs is false.

Is there an easy-to-describe counterexample? Andy Latto andy.latto@pobox.com