People go around saying this, but it isn't true: ... I stand corrected. I did know about the first issue (from one of Eliezer's postings elsewhere, IIRC), but figured that this wasn't absolutely critical as long as one didn't insist on building a self-improving AI, and was willing to use some cludgy workarounds. I hadn't noticed the second one, but it's obvious in retrospect (and sufficient for me to retract my statement).