
Recent Posts
 Logic without negation and falsehood December 11, 2016
 Logic without truth September 3, 2016
 Learning category theory: a necessary evil? April 3, 2016
Blogs I Follow
Author Archives: gentzen
Logic without negation and falsehood
In the last post, consideration related to partial functions lead us to present a logic without truth and implication, using the binary minus operation as a dual of implication and substitute for unary negation. But logic without implication and equivalence … Continue reading
Posted in Uncategorized
2 Comments
Logic without truth
Pi is wrong! But so what? It is neither new, nor complicated enough to count as real math! And suggestions that or might be even better show that it not clearcut either. I recently invested sufficient energy into some logical questions to … Continue reading
Posted in category theory, logic, partial functions
Tagged category theory, gentzen, logic
5 Comments
Learning category theory: a necessary evil?
The end of my last blog post (about isomorphism testing of reversible deterministic finite automata) explained how category theory gave me the idea that the simplified variant of my question about permutation group isomorphism should be easy to solve: The idea to consider … Continue reading
A canonical labeling technique by Brendan McKay and isomorphism testing of deterministic finite automata
A deterministic finite automaton (DFA) is a 5tuple, , consisting of a finite set of states a finite set of input symbols a (partial) transition function an initial state a set of accept states An isomorphism between two DFAs and … Continue reading
Posted in inverse semigroups, isomorphism, partial functions
Tagged inverse semigroups, isomorphism
4 Comments
On Zeros of a Polynomial in a Finite Grid: the AlonFuredi bound
Originally posted on Anurag's Math Blog:
My joint paper with Aditya Potukuchi, Pete L. Clark and John R. Schmitt is now up on arXiv: arXiv:1508.06020. This work started a few months back when I emailed Pete and John, pointing out an easy generalization…
Posted in Uncategorized
Leave a comment
Groupoids
Originally posted on Annoying Precision:
My current top candidate for a mathematical concept that should be and is not (as far as I can tell) consistently taught at the advanced undergraduate / beginning graduate level is the notion of a…
Posted in Uncategorized
Leave a comment
Reversibility of binary relations, substochastic matrices, and partial functions
After the last post, I decided that the next post should contain images. Next I decided that the time to publish another post has come. Here is an image of an acceptor finitestate machine, parsing the string “nice”. How can … Continue reading