Determines if a string is a palindrome

palin.erl

-module(palin).
-export([palindrome_check/1]).

rem_punct(String) ->
    lists:filter(fun (Ch) ->
                     not(lists:member(Ch, "\"\'\t\n "))
                 end, String).

to_small(String) -> lists:map(fun(Ch) ->
                                case ($A =< Ch andalso Ch =< $Z) of
                                    true  -> Ch + 32;
                                    false -> Ch
                                end
                              end, String).

palindrome_check(String) ->
    Normalize = to_small(rem_punct(String)),
    lists:reverse(Normalize) == Normalize.

server.erl

-module(server).
-import(palin, [palindrome_check/1]).
-export([server/1]).

server(Pid) ->
    receive
        {check, Msg} ->
            IsPalindrome = isPalindrome(palin:palindrome_check(Msg)),
            Pid ! {result, io:format("~p is~p a palindrome~n", [Msg, IsPalindrome])},
            server(Pid);
        stop         -> io:format("stopped.~n");
        _            ->
            io:format("Error: unrecognized message.~n"),
            server(Pid)
    end.

isPalindrome(Result) ->
    case Result of
      true  -> "";
      false -> " not "
    end.