Written: Jan. 20, 2012

The better half of WZ pair, the "W", the first (and the more complex one of the) "pair of complex variables" (see footnote at p.2 of this masterpiece) left this world on Jan. 7, 2012. But only his body!

W was an outstanding *combinatorialist*, of course, but as I have already said in
this tribute
his *influence* and *vision* far transcends any one specialty.

In the Philadelphia Inquirer
**deeply intertwined**". True, of course, but **not only**
"teaching and research". Also *pure* and *applied*, *conceptual* and *computational*,
*problem solving* and *theory building*, *global* and *local*,
*strategic* and *tactical* and so on and so forth.

It is a mark of an interesting person that his or her children are interesting and diversified in their
talents, interests, and activities. Herb had three wonderful children:
Susan, a brilliant Chinese scholar,
David, a brilliant lawyer, and
Peter, a brilliant paleontologist. And he had
*twenty eight* brilliant
academic children, all different than
each other, including a
a bishop.
He also has six brilliant biological grandchildren, and 21 talented *academic* grandchildren.

And Herb was such a *mensch*. He made sure that
Sister Celine would get
the recognition that she so deserved, and flew his plane to her convent, in order to conduct
a historic interview that is preserved for posterity.

W was also one of the greatest lecturers that I have ever known. For an example, watch his great lecture whimsically titled "How to lose as little as possible": part 1, part 2 part 3, part 4.

And W was not only a great problem-solver, but like Erdos, also a great problem-poser. Please try to solve any of his unsolved problems, that he only posted a year ago. Myself, I have no clue how to solve any of them, and I could only say something about the sixth problem.

On Feb. 2, 2012, I will give a talk about W at the
Rutgers Experimental Mathematics Seminar,
that would be (like all talks in that seminar where the speaker agrees)
videotaped and uploaded to YouTube, and I will put a link to it as soon as
it is up. There I will highlight some of my favorite W gems,
including the Greene-Nijenhuis-Wilf
probabilistic proof of the hook-length-formula
and the *gorgeous*
Calkin-Wilf Recounting of Fractions.

Added Feb. 2, 2012: Edinah Gnang kindly filmed and uploaded my talks, and as I promised here are the links: part 1, part 2.

Added Feb. 10, 2012: To experiment with the lovely Greene-Nijenhuis-Wilf algorithm, you are welcome to play with the Maple package GreeneNijenhuisWilf.

For example, the input file yields the output file, and the input file yields the output file.

Added Jan. 8, 2013: Ruth Wilf just sent me this great photo of Herb.

Opinions of Doron Zeilberger