The lattice of convexities of partial monounary algebras
A class of partial monounary algebras is called a convexity if it is closed under homomorphic images, direct products and convex relative subalgebras. We prove that the collection of all convexities of partial monounary algebras forms a countable set. Further, each convexity can be generated by at most two algebras.
KeywordsPartial monounary algebra Convex relative subalgebra Convexity
Mathematics Subject Classification08A60
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