:% class
	:a:b = "foo"
	:c = "bar"

:o = class
:a = class
::b = class

0 = {o == a}
0 = {o == b}
1 = {o!constant == b}

~ o.b := "haha"

0 = {o!constant == b}

~ a.b := "haha"

1 = {o!constant == a!constant}

~ o.b := "foo"

0 = {o!constant == b}