Blogs I Follow
- Not Even Wrong
- More Quantum
- Shtetl-Optimized
- Mathematics without Apologies, by Michael Harris
- Windows On Theory
- Thoughts
- ThatsMaths
- Tobias J. Osborne's research notes
- What Immanuel Kant teach you
- Quantum Frontiers
- MyCQstate
- Neil Barton
- Computational Semigroup Theory
- Math ∩ Programming
- ErdosNinth
- in theory
- Anurag's Math Blog
- Annoying Precision
- njwildberger: tangential thoughts
- Combinatorics and more
- What's new
- Bits of DNA
- Turing Machine
- My Brain is Open
- Gödel's Lost Letter and P=NP
- Mathematical Formalities
-
Recent Posts
- Blackbox oracles and function classes December 23, 2025
- Am I an engineer? December 23, 2024
- Proving formal definitions of informal concepts November 4, 2023
- Getting started without a pre-existing understanding of non-standard natural numbers September 9, 2022
- True randomness and ontological commitments February 28, 2022
- Why mathematics? February 19, 2022
- Incredibly awesome, but with overlength September 3, 2021
- Fields and total orders are the prime objects of nice categories January 30, 2021
- Prefix-free codes and ordinals May 11, 2020
- Isomorphism of labeled uniqueness trees April 20, 2020
- Defining a natural number as a finite string of digits is circular August 17, 2019
- Theory and practice of signed-digit representations April 16, 2019
- A list of books for understanding the non-relativistic QM — Ajit R. Jadhav’s Weblog November 25, 2018
- I’m not a physicist April 29, 2018
- ALogTime, LogCFL, and threshold circuits: dreams of fast solutions November 2, 2017
- A subset interpretation (with context morphisms) of the sequent calculus for predicate logic September 24, 2017
- Logic without negation and falsehood December 11, 2016
- Logic without truth September 3, 2016
- Learning category theory: a necessary evil? April 3, 2016
- A canonical labeling technique by Brendan McKay and isomorphism testing of deterministic finite automata November 15, 2015
- On Zeros of a Polynomial in a Finite Grid: the Alon-Furedi bound September 19, 2015
- Groupoids August 3, 2015
- Reversibility of binary relations, substochastic matrices, and partial functions March 22, 2015
- Algebraic characterizations of inverse semigroups and strongly regular rings December 6, 2014
- Gentzen’s consistency proof is more impressive than you expect December 5, 2013
Recent Comments
- gentzen on Am I an engineer?
- gentzen on Am I an engineer?
- Peter Morgan on I’m not a physicist
- Peter Morgan on True randomness and ontological commitments
- gentzen on Fields and total orders are the prime objects of nice categories
- Proving formal definitions of informal concepts | Gentzen translated on Incredibly awesome, but with overlength
- gentzen on Getting started without a pre-existing understanding of non-standard natural numbers
- vegafrank on Getting started without a pre-existing understanding of non-standard natural numbers
- Christopher on Getting started without a pre-existing understanding of non-standard natural numbers
- gentzen on True randomness and ontological commitments
- none on True randomness and ontological commitments
- True randomness and ontological commitments | Gentzen translated on Why mathematics?
- Fields and total orders are the prime objects of nice categories | Gentzen translated on Defining a natural number as a finite string of digits is circular
- Fields and total orders are the prime objects of nice categories | Gentzen translated on Algebraic characterizations of inverse semigroups and strongly regular rings
- gentzen on ALogTime, LogCFL, and threshold circuits: dreams of fast solutions
Category Archives: partial functions
Blackbox oracles and function classes
After spending a long time to work out the function classes for bounded alternating Turing machines, I felt stupid that it took me so long to see the obvious: They are the functions computable by deterministic machines (with appropriate resource … Continue reading
Posted in complexity, computability, partial functions
Leave a comment
A subset interpretation (with context morphisms) of the sequent calculus for predicate logic
The previous two posts used the sequent calculus with a subset interpretation: We work with sequents , and interpret the propositions (and ) as subsets of some universe set . We interpret the sequent itself as . While writing the … Continue reading
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 clear-cut either. I recently invested sufficient energy into some logical questions to … Continue reading
A canonical labeling technique by Brendan McKay and isomorphism testing of deterministic finite automata
A deterministic finite automaton (DFA) is a 5-tuple, , 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 automata, inverse semigroups, isomorphism, partial functions
4 Comments
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 finite-state machine, parsing the string “nice”. How can … Continue reading
Gentzen translated 
