Abstract
A hypersubstitution of type (2,2) is a map σ which takes the binary operation symbols f and g to binary terms σ(f) and σ(g). Any such σ can be inductively extended to a map \(\hat{\sigma}\) on the set of all terms of type (2,2). By using this extension on the set Hyp(2,2) of all hypersubstitutions of type (2,2) a binary operation can be defined. Together with the identity hypersubstitution mapping f to f(x 1,x 2) and g to g(x 1,x 2) the set Hyp(2,2) forms a monoid. This monoid is isomorphic to the endomorphism monoid of the clone of all binary terms of type (2,2). We determine all idempotent elements of this monoid. The results can be applied to the equational theory of Universal Algebra.
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References
Denecke, K., Koppitz, J.: Finite Monoids of Hypersubstitutions of Type τ=(2). Semigroup Forum 56, 265–275 (1998)
Denecke, K., Wismath, S.L.: The Monoid of Hypersubstitutions of type (2). Contributions to General Algebra, 10. In: Proceedings of the Klagenfurt Conference 1997, May 29–June 1, pp. 109–126. Johannes Heyn, Klagenfurt (1998)
Denecke, K., Wismath, S.L.: Hyperidentities and Clones. Gordon and Breach, London (2000)
Denecke, K., Lau, D., Pöschel, R., Schweigert, D.: Hypersubstitutions, hyperequational classes and clone congruences. Contrib. Gen. Algebra 7, 97–118 (1991)
Denecke, K., Jampachon, P., Wismath, S.L.: Clones of n-ary algebras. J. Appl. Algebra Discrete Math. 1(2), 141–158 (2003)
Menger, K.: The algebra of functions: past, present, future. Rend. Math. 20, 409–430 (1961)
Wismath, S.L.: The monoid of hypersubstitutions of type (n). Southeast Asian Bull. Math. 24, 115–128 (2000)
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Communicated by Mikhail Volkov.
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Cangpas, T., Denecke, K. All idempotent hypersubstitutions of type (2,2). Semigroup Forum 76, 525–539 (2008). https://doi.org/10.1007/s00233-008-9048-6
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DOI: https://doi.org/10.1007/s00233-008-9048-6