Laurence Kirby Professor of Mathematics, Baruch College of the City University of New York 
Two views of the beginning of the process of generating all finite sets:

Building up the finite sets The first 33 sets, adductive form
 Click here for another, higher resolution picture...        Click here for a related animation (size 250K)
My office is Room 6-222 in the Vertical Campus of  Baruch College, my office phone number is (646) 312-4127,
and you can  send me e-mail . My office hours for Spring 2008 are on Tuesdays, 12:25-2:25pm.
A Hydra February 2008: Thanks to Andrej Bauer, you can now play the Hydra game online. (Click on "Try the game online" near the bottom of the page.)
Click on the image at right for a mathematical puzzle-poem. Only 3 people have ever solved it. Be the fourth person to send me the solution! Tree: a mathematical puzzle-poemTree
 
Article: Addition and multiplication of sets (200K pdf file)
I received a B.A. and M.A. from Cambridge University, and a Ph.D. from Manchester University in 1977. After spells in Paris and Princeton, I joined Baruch College as a professor in 1982.
My research area is Mathematical Logic, and the philosophical background to my research has been the question:
What is the relationship between language and reality?
(assuming there is such a thing as reality).
I have studied this question in the technical context of the formal "language" of arithmetic, and the "reality" of the structure of the natural numbers (0,1,2,3, etc.) that arithmetic purports to describe. In fact, no reasonable language can capture this reality exactly and uniquely: there are always "non-standard" structures that do the job too. These are the models of arithmetic.
More recently I have explored more general ways to erode the distinction between language ("the dress of thought" -- Dr. Johnson) and the thought it dresses, in a philosophical study of logical principles for reasoning about natural objects, as opposed to the abstract objects of mathematics. You can read about this in my article,
 Steps towards a logic of natural objects.
Questions about natural objects and feasibility led to my current investigations into finite sets, and the pictures above.
I explore the same general questions in poetry, song and music,
in the person of my alter ego, T. G. Vanini .
 Baruch College Mathematics Department 
  Logic in the New York metropolitan area
Ten-fingers toad
Last updated 13.2.2008