gistfile1.txt

$ erlc nick.erl && erlc vanessa.erl

1> Me = nick:new("Mountain View", "CA").
{nick,"Mountain View","CA"}
2> Me:city().                           
nick:city/0 -> "Mountain View" 
ok
3> Me:state().
nick:state/0 -> "CA"
ok
4> Vanessa = vanessa:new("Mountain View", "CA").
{vanessa,{nick,"Mountain View","CA"},"Mountain View","CA"}
5> Vanessa:city().
child:city/0 -> "Mountain View" 
ok
6> Vanessa:state().
nick:state/0 -> "CA"
ok
7> 

nick.erl

-module(nick, [City, State]).

-export([city/0, state/0]).

state() ->
    io:format("nick:state/0 -> ~p~n", [State]).

city() ->
    io:format("nick:city/0 -> ~p ~n", [City]).

vanessa.erl

-module(vanessa, [City, State]).
-extends(nick).
-export([city/0]).

city() ->
    io:format("child:city/0 -> ~p ~n", [City]).