libghc-semigroups-doc 0.18.5-2build1 (armhf binary) in ubuntu focal

 It contains a Haskell 98 logically-uninhabited data type used to
 indicate that a given term should not exist.
 .
 This package provides the documentation for a library for the Haskell
 programming language.
 See http://www.haskell.org/ for more information on Haskell.