Hereditarily Finitely Based Monoids of Extensive Transformations
Semigroups, Monoids, Transformations, Extensive, Order-Preserving, Finitely Based, Hereditarily Finitely Based
It is shown that the monoid En of extensive transformations of a chain of order n is hereditarily finitely based if and only if n ≤ 3. It follows that the submonoid OEn of order-preserving transformations in En is also hereditarily finitely based if and only if n ≤ 3.
Lee, Edmond W. H., "Hereditarily Finitely Based Monoids of Extensive Transformations" (2009). Mathematics Faculty Articles. 155.