Commuting fully invariant congruences on free completely regular semigroups

Pastijn, F.

doi:10.1090/S0002-9947-1991-1016809-9

Commuting fully invariant congruences on free completely regular semigroups
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Trans. Amer. Math. Soc. 323 (1991), 79-92 Request permission

Abstract:

We show that "almost all" fully invariant congruences on every free completely regular semigroup commute. From this it is shown that the lattice of completely regular semigroup varieties is arguesian.

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