Install libghc-generics-sop-doc by entering the following commands in the terminal:
sudo apt update sudo apt install libghc-generics-sop-doc
Description:
Generic Programming using True Sums of Products; documentation
A library to support the definition of generic functions. Datatypes are viewed in a uniform, structured way: the choice between constructors is represented using an n-ary sum, and the arguments of each constructor are represented using an n-ary product. . This package provides the documentation for a library for the Haskell programming language. See http://www.haskell.org/ for more information on Haskell.
Homepage: http://hackage.haskell.org/package/generics-sop
Version: 0.3.1.0-1
Section: universe/doc