[Haskell-beginners] Error Message when trying to solve alphametic(SEND + MORE = MONEY)

[Sok Ha Chang]

Hi.
I’m new to Haskell.
Use Haskell Platform on MacBook Air.
$ ghc --version
The Glorious Glasgow Haskell Compilation System, version 7.6.3

I’m try to solve alphametic.
SEND + MORE = MONEY

Here is code…
----------------------------------------------------------------------------------------------------------
import Data.List

decryp :: [Int] -> String -> String
decryp (s:e:n:d:o:r:y:[]) a =
	if send + more == money then expr:a else a
	where 	
		send 	= s * 1000 + e * 100 + n * 10 + d
		more 	= 1000 + o * 100 + r * 10 + e
		money 	= 10000 + o * 1000 + n * 100 + e * 10 + y
		expr 	= show send ++ "+" ++ show more ++ "=" show money

decrypSolver :: [String]
decrypSolver =
	foldr decryp [] (permutations 7 [0, 2, 3, 4, 5, 6, 7, 8, 9])
----------------------------------------------------------------------------------------------------------

Error Messages is
./decrypSolver.hs: line 10, column 60:
  Couldn't match expected type `(a0 -> String) -> Int -> [Char]'
              with actual type `[Char]'
  The function `"="' is applied to two arguments,
  but its type `[Char]' has none
  In the second argument of `(++)', namely `"=" show money'
  In the second argument of `(++)', namely
    `show more ++ "=" show money’
----------------------------------------------------------------------------------------------------------

How can I fix this?

Thank you.

Sincerely, S. Chang