Formal languages

Equivalence problem

In theoretical computer science and formal language theory, the equivalence problem is the question of determining, given two representations of formal languages, whether they denote the same formal language. The complexity and decidability of this decision problem depends upon the type of representation under consideration. For instance, in the case of finite-state automata, equivalence is decidable, and the problem is PSPACE-complete.Further, in the case of deterministic pushdown automata, equivalence is decidable, Géraud Sénizergues won the Gödel Prize for this result. Subsequently the problem was shown to lie in TOWER, the least non-elementary complexity class. It becomes an undecidable problem for pushdown automata or any machine that can decide context-free languages or more powerful languages. (Wikipedia).

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Equivalence Relations Definition and Examples

Please Subscribe here, thank you!!! https://goo.gl/JQ8Nys Equivalence Relations Definition and Examples. This video starts by defining a relation, reflexive relation, symmetric relation, transitive relation, and then an equivalence relation. Several examples are given.

From playlist Abstract Algebra

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12 Equivalence relations

Put all three properties of binary relations together and you have an equivalence relation.

From playlist Abstract algebra

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Equivalence Relations!

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From playlist Proofs

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From playlist Abstract Algebra 1

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Discrete Math - 9.5.1 Equivalence Relations

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From playlist Discrete Math I (Entire Course)

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From playlist Short Talks by Postdoctoral Members

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From playlist Set Theory by Mathoma

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From playlist Relations

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23. Acid-Base Titrations Part I

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From playlist MIT 5.111 Principles of Chemical Science, Fall 2014

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Lec 24 | MIT 5.111 Principles of Chemical Science, Fall 2005

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From playlist MIT 5.111 Principles of Chemical Science, Fall 2005

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Sanjay Mishra: Preservation of Properties during Topological Equivalence of Function Space

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From playlist 39th Annual Geometric Topology Workshop (Online), June 6-8, 2022

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Zlil Sela - Envelopes and equivalence relations in a free group

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Juhani Karhumäki : k-abelian equivalence: an equivalence relation in between the equality...

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MATH1081 Discrete Maths: Chapter 2 Question 18

This problem is about equivalence relation and equivalence classes. Presented by Peter Brown of the School of Mathematics and Statistics, Faculty of Science, UNSW.

From playlist MATH1081 Discrete Mathematics

Related pages

Pushdown automaton | Deterministic pushdown automaton | Undecidable problem | Nonelementary problem | Theoretical computer science | Context-free language | Gödel Prize | Decision problem | PSPACE-complete