Lua Call ambiguity

function y(arg)
    print("y:", arg)
    geg = geg + 100
end

function g(arg)
    print("g:", arg)
    geg = geg + 10
    return y
end

function f(arg)
    print("f:", arg)
    geg = geg + 1
    return g
end

-- two seperate f() calls with no arguments.
geg = 0
f();(f)()
print("value:", geg)
print("--")

-- calls f(), g(f), y()
geg = 0
f() (f)()
print("value:", geg)
print("--")

-- two seperate f() calls with no arguments.
geg = 0
f()  f ()
print("value:", geg)