denotator type named class expression A named class expression is a logical expression that is given a name. The name can be used in place of the expression. Alan Ruttenberg named class expression named class expressions are used in order to have more concise logical definition but their extensions may not be interesting classes on their own. In languages such as OWL, with no provisions for macros, these show up as actuall classes. Tools may with to not show them as such, and to replace uses of the macros with their expansions