Recursive Unsolvability of a Problem of Thue¶
Post, E. L. (1947). Recursive Unsolvability of a Problem of Thue. 12(1), 1-11.
Cited by¶
1 citation across 1 artifact.
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Primes¶
- Monoid
- Decidability does not transfer: the word problem for finitely presented monoids is undecidable, so knowing that a structure is a monoid does not mean two expressions in it can be compared.
This sourceProves the word problem for a finitely presented semigroup, given as a Thue system on words over a finite alphabet, recursively unsolvable; the finitely presented monoid case is the same result on the free monoid with the empty word admitted.
- Decidability does not transfer: the word problem for finitely presented monoids is undecidable, so knowing that a structure is a monoid does not mean two expressions in it can be compared.
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Registry ID ref:00c3b93f7ce1 · see in the full table