They are two kinds of undefined-ness, one for runtime and one for compile-time.

Just improving on an ambiguous name.

Context-sensitive layout means you get a different structure each time you use it.

No real contradictions in anybody's story.

Patterns are predictable, which is not always a good thing.

You can do the conversion in two steps using things you already have.

Digging into what the compiler sees.

If you don't know what it operates on or produces, then it operates on or produces itself.

Usually not exploitable, but the script kiddies don't know that.

Six possibilities, but only five useful ones.