>>>>> "T" == Tammo Freese <tammo.freese / offis.de> writes: T> Does the bug that you describe also occur with the latest stable T> snapshot on your system? Probably because the patch is #if defined __CYGWIN__ #define log(x) ((x) < 0.0 ? nan() : log(x)) #define log10(x) ((x) < 0.0 ? nan() : log10(x)) #endif and on Solaris 2.7 moulon% man log Mathematical Library log(3M) NAME log - natural logarithm function SYNOPSIS cc [ flag ... ] file ... -lm [ library ... ] #include <math.h> double log(double x); DESCRIPTION The log() function computes the natural logarithm of x, loge(x). The value of x must be positive. RETURN VALUES Upon successful completion, log() returns the natural loga- rithm of x. If x is NaN, NaN is returned. If x is less than 0, -HUGE_VAL or NaN is returned and errno ^^^^^^^^^^^^^^^^ is set to EDOM. [...] moulon% I don't know if it exist a flag to give to cc to have always NaN Guy Decoux