V = {'&', ',', ';', A-Z, a-z, 0-9,'(', ')'}
E = {<letter>,<char>,<type>,<string>,<header>}
P = {
<letter>::=a|b..|z|A|B..|Z
<char>::=<letter>|0|1..|9
<type>::=int|bool|void|char
<string>::=<letter>|<string><char>
<header>::=<type> <string>({<type>[&]<string>});
}
ó = <header>