On a side note, in ECL I made sure that (EQUALP #1=(/ 0.0 0.0) #1#) => NIL because EQUALP uses by definition #'= to compare numbers. SBCL does not seem to get this right. Juanjo -- Instituto de Física Fundamental, CSIC c/ Serrano, 113b, Madrid 28006 (Spain) http://juanjose.garciaripoll.googlepages.com