Using the Alpoge-Claude amazing counterexample of the Jacobian Conjecture to Generate Many More of Them
By Shalosh B. Ekhad and Doron Zeilberger
.pdf
.tex
[Not Yet Written]
First Written: Aug. 3, 2026
This version: Aug. 3, 2026
Maple package
-
Alpoge.txt,
a Maple package to generate many counterexamples of the Jacobian Conjecutre, using, and inspired by, the Alpoge-Claude counterexample of the Jacobian conjecture
Sample Input and Output for Alpoge.txt
If you want to see the five-parameter counterexample, inspired by the Alpoge-Claude example, by "cheating" and looking at the monomials that showed up,
and setting a generic transormation with the same monomials but arbitrary coefficients
then the input gives the
output.
[Note that this is hard-wired in the Maple packge Alpoge.txt by procedure GenClaude(x,k). Also note that it took less than a second!]
But that was "cheating" since we used the same template. For a still restricted, but much larger haystack, still with total degrees 7,6,4
then the input gives the
output.
Note that we got the same output, nothing new!
If you want to see all the counterexamples where the largest degree is 6 (with this restricted choice of supports)
then the input gives the
output.
[Note that it is the empty set, nothing was found. Of course, it is still possible that there are degree 6 counterexmaples with larger supports.]
If you want to see a more exhaustive search for transoformations of degree 7 (but still not fully general)
then the input gives the
output.
[Note the nothing new was found]
If you want to see the analogous thing for degree 8
then the input gives the
output.
[Note: it seems that we found a new one! Alas the degree ≤ 8 turned out to be degree 6, so the new one
is equivalent (via a change of parameters) to GenClaude(x,k)]
If you want to see the truncation to total degree 20, of the formal power series inverse transformation of Claude(x)
then the input gives the
output.
Personal Journal of Shalosh B. Ekhad and Doron Zeilberger
Doron Zeilberger's Home Page