Hi Juanjo, ECL reports wrong value for the sign of -0.0. > *features* (:LINUX :FORMATTER :IEEE-FLOATING-POINT :RELATIVE-PACKAGE-NAMES :DFFI :CLOS-STREAMS :CMU-FORMAT :UNIX :ECL-PDE :DLOPEN :CLOS :BOEHM-GC :ANSI-CL :COMMON-LISP :ECL :COMMON :PENTIUM3 :FFI :PREFIXED-API) > (float-sign -0.0) 0.0 The correct value is -1.0. -- Gaby