Show substitutions in ghci

问题

How can I see substitutions of variable names to their values in haskell? e.g.

    c2i zero
==> c2i (Chr (\x y -> y))
==> (\x y -> y) (+ 1) 0
==> 0

As explained in this answer.

来源：https://stackoverflow.com/questions/36650044/show-substitutions-in-ghci