Date: Wed, 20 May 87 19:27:34 PDT From: edsel!bhopal!jonl@navajo.stanford.edu (Jon L White) Isn't this a bug? It certainly provides a loophole for non-portable code that isn't reasonably detectable as non-portable. No. As Fahlman explained clearly in an earlier message, providing extensions that make it harder to determine portability is in no way a "bug" or "violation of Common Lisp".