In automata theory, an alternating finite automaton (AFA) is a nondeterministic finite automaton whose transitions are divided into existential and universal transitions. For example, let A be an alternating automaton. * For an existential transition , A nondeterministically chooses to switch the state to either or , reading a. Thus, behaving like a regular nondeterministic finite automaton. * For a universal transition , A moves to and , reading a, simulating the behavior of a parallel machine. Note that due to the universal quantification a run is represented by a run tree. A accepts a word w, if there exists a run tree on w such that every path ends in an accepting state. A basic theorem states that any AFA is equivalent to a deterministic finite automaton (DFA), hence AFAs accept exactly the regular languages. An alternative model which is frequently used is the one where Boolean combinations are in disjunctive normal form so that, e.g., would represent . The state tt (true) is represented by in this case and ff (false) by . This representation is usually more efficient. Alternating finite automata can be extended to accept trees in the same way as tree automata, yielding alternating tree automata. (Wikipedia).
Transforming an NFA into a DFA
Any non-deterministic finite state automaton (NFA) can be transformed into an equivalent deterministic finite state automaton (DFA). In this video we'll see how to make the transformation by systematically exploring an NFA.
From playlist Discrete Structures
Cellular Automata Rule-Generating Polynomials
Cellular Automata rules are represented by integers where we encode the output of the function without knowing the details on how it might be implemented. The CellularAutomaton function in Mathematica only requires these integers, along with the values of r and k, to evolve rules for a giv
From playlist Wolfram Technology Conference 2022
Cellular Automata: Rule 110 + Conway’s Game of Life
A 1D cellular automaton, Rule 110 (bottom), being fed as input to a 2D cellular automaton, Conway’s Game of Life (top). How It Works: The colors represent a gird of cells (pixels) that are alive (are white pixels) or are dead (non-white pixels, where the color represents how long it's be
From playlist Math Animations
Mining and Cataloguing the Computational Universe of Cellular Automata
One-dimensional cellular automata rules are defined by k number of values with r as the range of neighboring cells used in the rule. As an example, the elementary cellular automata (ECA) is the rule set where k = 2 and r = 1. Rodrigo Obando shows how they are able to find a particular rule
From playlist Wolfram Technology Conference 2020
Automorphy: Automorphy Lifting Theorems I (continued)
David Geraghty Princeton University; Institute for Advanced Study March 10, 2011 For more videos, visit http://video.ias.edu
From playlist Mathematics
Cellular Automata are a fantastic demonstration of how a simple set of rules can elicit a complex emergent behaviour. In this video I show John Conway's Game Of Life implemented in quick and simple C++ at the command line. Github: https://github.com/OneLoneCoder/Javidx9/blob/master/Consol
From playlist Interesting Programming
Adventures in Automata with a Theorem-Prover
Public Lecture by Jeffrey Shallit (University of Waterloo) Here is the weblink for the publicly-available prover https://cs.uwaterloo.ca/~shallit/walnut.html
From playlist Public Lectures
Diego Figueira: Semistructured data, Logic, and Automata – lecture 1
Semistructured data is an umbrella term encompassing data models which are not logically organized in tables (i.e., the relational data model) but rather in hierarchical structures using markers such as tags to separate semantic elements and data fields in a ‘self-describing’ way. In this
From playlist Logic and Foundations
A regular expression, regex or regexp (sometimes called a rational expression) is a sequence of characters that define a search pattern. Usually such patterns are used by string searching algorithms for "find" or "find and replace" operations on strings, or for input validation. It is a te
From playlist Regex
Deterministic Finite State Machines - Formal Languages and Automata
We introduce deterministic finite state machines / deterministic finite state automata, how to define them, and how to take a picture and convert it to the formal representation. We also talk about languages that machines accept. 0:00 - [Intro] 1:32 - [State Transition Table] 3:07 - [Form
From playlist Formal Languages and Automata
History of Science and Technology Q&A (November 30, 2022)
Stephen Wolfram hosts a live and unscripted Ask Me Anything about the history of science and technology for all ages. Find the playlist of Q&A's here: https://wolfr.am/youtube-sw-qa Originally livestreamed at: https://twitch.tv/stephen_wolfram If you missed the original livestream of thi
From playlist Stephen Wolfram Ask Me Anything About Science & Technology
The Rules of Powers: Zero Exponent, Negative Exponents // Math Minute [#49] [ALGEBRA] [ARITHMETIC]
Exponentiation is the special operation that upgrades addition into multiplication. From this key feature, we can generate all the rest of our power rules. When you multiply exponential expressions with a common base, you add the powers. When you divide such expressions, you subtract the p
From playlist Math Minutes
Diego Figueira: Semistructured data, Logic, and Automata – lecture 2
Semistructured data is an umbrella term encompassing data models which are not logically organized in tables (i.e., the relational data model) but rather in hierarchical structures using markers such as tags to separate semantic elements and data fields in a ‘self-describing’ way. In this
From playlist Logic and Foundations
Émilie Charlier: Logic, decidability and numeration systems - Lecture 1
Abstract: The theorem of Büchi-Bruyère states that a subset of Nd is b-recognizable if and only if it is b-definable. As a corollary, the first-order theory of (N,+,Vb) is decidable (where Vb(n) is the largest power of the base b dividing n). This classical result is a powerful tool in ord
From playlist Mathematical Aspects of Computer Science
Discrete Structures: Finite state machines
Introduction to finite state machines and regular expressions.
From playlist Discrete Structures
Laurent Bartholdi: Quadratic polynomials
HYBRID EVENT Recorded during the meeting "Advancing Bridges in Complex Dynamics" the September 21, 2021 by the Centre International de Rencontres Mathématiques (Marseille, France) Filmmaker: Guillaume Hennenfent Find this video and other talks given by worldwide mathematicians on CIRM
From playlist Dynamical Systems and Ordinary Differential Equations
Find this video and other talks given by worldwide mathematicians on CIRM's Audiovisual Mathematics Library: http://library.cirm-math.fr. And discover all its functionalities: - Chapter markers and keywords to watch the parts of your choice in the video - Videos enriched with abstracts, b
From playlist Mathematical Aspects of Computer Science
Learn how to divide rational expressions. A rational expression is an expression in the form of a fraction, usually having variable(s) in the denominator. Recall that to divide by a fraction, we multiply by the reciprocal of the fraction. The same rule applies when we want to divide by a r
From playlist How to Divide Rational Expressions #Rational
4. Pushdown Automata, Conversion of CFG to PDA and Reverse Conversion
MIT 18.404J Theory of Computation, Fall 2020 Instructor: Michael Sipser View the complete course: https://ocw.mit.edu/18-404JF20 YouTube Playlist: https://www.youtube.com/playlist?list=PLUl4u3cNGP60_JNv2MmK3wkOt9syvfQWY Quickly reviewed last lecture. Defined context free grammars (CFGs) a
From playlist MIT 18.404J Theory of Computation, Fall 2020