Algebraic properties and dismantlability of finite posets
The authors generalize some known results to arbitrary finite posets. They show that for every finite poset the existence of Gumm or Jónsson operations is equivalent to the existence of a near unanimity function in the clone of isotone operations. Finite connected posets satisfying these equivalent conditions are characterized by the property that their idempotent subalgebras are dismantlable. They obtain that the problem of determining if a finite poset admits a near unanimity function is decidable.
scientific article; zbMATH DE number 1018619