28 citations · 196 across the 41 of their papers we have counts for
43 papers
Associative-commutative spectra for some varieties of groupoids
Jia Huang, Erkko Lehtonen
The associative spectrum of a groupoid (i.e., a set with a binary operation) measures its nonassociativity while the associative-commutative spectrum measures both nonassociativity…
Associativity conditions for linear quasigroups and equivalence relations on binary trees
Erkko Lehtonen, Tamás Waldhauser
We characterise the bracketing identities satisfied by linear quasigroups with the help of certain equivalence relations on binary trees that are based on the left and right depths…
-preclones and the Galois connection -, Part I
Peter Jipsen, Erkko Lehtonen, Reinhard Pöschel
We consider -operations in which each argument is assigned a signum representing a "property" such as being order-preserving or order-reversing…
Near-unanimity-closed minions of Boolean functions
Erkko Lehtonen
The near-unanimity-closed minions of Boolean functions, i.e., the clonoids whose target algebra contains a near-unanimity function, are completely described. The key concept toward…
Galois theory for analogical classifiers
Miguel Couceiro, Erkko Lehtonen
Analogical proportions are 4-ary relations that read "A is to B as C is to D". Recent works have highlighted the fact that such relations can support a specific form of inference,…
The associative-commutative spectrum of a binary operation
Jia Huang, Erkko Lehtonen
We initiate the study of a quantitative measure for the failure of a binary operation to be commutative and associative. We call this measure the associative-commutative spectrum a…