-- scope --

do
    -- variable y not in global scope anymore --
    local y = 21
end

function foo()
    -- on the first foo call, the x below will be defined globally --
    -- oy oy oy ooooooy --
    x = 13;

    -- y is not seen here --
    print(y)
end

print(x) -- no x defined --
foo()
print(x) -- x defined after call to foo --