-module(dialyzer_example).
-compile(export_all).

%%% For dialyzer to function properly it is recommended that
%%% all functions have spec defined in this manner.  Without
%%% this dialyzer guesses the input and output type which is
%%% not as good as specifying them explicitly.
-spec main() -> ok.
main() ->
    io:format("Read code, comments and use 'dialyzer ~p' command to see the output.~n", [?FILE]),
    ok.

%%% If we do not specify -spec() Dialyzer can infer the type to be 
%%%   add(number(), number()) -> number()
%%% Same can also be found using typer from linux shell as
%%%   typer f077_dialyzer.erl
%%%
add(A, B) ->
    A+B.