The Lattice Theory Homepage


J. B. Nation's counter example to the finite height conjecture

This lattice is infinte and subdirectly irreducible but the variety it generates contains only finitely many other varieties, refuting an old conjecture. Think of this lattice as wrapped around a cylinder so that the elements at the sides with the same labels are identified. Note the middle part of this diagrams moves up when going from left to right so that when it is wrapped around the cylinder it is helical.

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5 May 1999 (minor revisions 2011)
Ralph Freese
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