Yes, that's a problem of me not being a native english speaker.
"All x aren't y" may mean "not all x are y" in my tongue.
Not a single x is y is more what we would say in the previous case.
But in our case we would say there are x that aren't y.
If thinking is definable, it is wrong that all statements about it are unverifiable (i.e. there are statements about it that are verifiable.)
