So, according to you “the act of not existing” is not a thing which exists.
Let us consider Jesus older brother. I think we can all agree that Jesus’ older brother did not exist. Hence we can correctly say that “Jesus older brother in in the act of not existing”. However, you tell us that “the act of not existing” is not a thing which exists. Therefore, since Jesus older brother cannot have a property which does not exist, we must say that Jesus older brother is not in the “act of not existing”. How can he be in the act of something non-existent? Hence, by the law of the excluded middle, if Jesus older brother cannot be in the “act of not existing” then he must be in the “act of existing”.
Following your logic shows that anything I chose to think of exists. Since this conclusion is obviously false, you logic is in error.
This is a proof by contradiction. Your logic fails.
You have also not dealt with my point that your logic does not depend on the causative nature of its subject. This is a further flaw for you to deal with.
rossum