+ package:cabal-install-solver

(+) :: Num a => a -> a -> a
cabal-install-solver Distribution.Solver.Compat.Prelude
(++) :: [a] -> [a] -> [a]
cabal-install-solver Distribution.Solver.Compat.Prelude
Append two lists, i.e., 
[x1, ..., xm] ++ [y1, ..., yn] == [x1, ..., xm, y1, ..., yn]
[x1, ..., xm] ++ [y1, ...] == [x1, ..., xm, y1, ...]
If the first list is not finite, the result is the first list. WARNING: This function takes linear time in the number of elements of the first list.
(<+>) :: Doc -> Doc -> Doc
cabal-install-solver Distribution.Solver.Compat.Prelude
Beside, separated by space, unless one of the arguments is empty. <+> is associative, with identity empty.