Reflections and powers of multisorted minions

Erkko Lehtonen, Reinhard Pöschel
2021 Algebra Universalis  
AbstractClasses of multisorted minions closed under extensions, reflections, and direct powers are considered from a relational point of view. As a generalization of a result of Barto, Opršal, and Pinsker, the closure of a multisorted minion is characterized in terms of constructions on multisorted relation pairs which are invariant for minions.
doi:10.1007/s00012-020-00707-0 fatcat:eoe5uzusdbdptaevrkugo2awwa