Dear All, Analysing a failure of my code I found the reason in the absence of conjugate() method for cosh and sinh functions. Is there a fundamental reason for this? Or shall I prepare a patch defining them similarly to this: static ex cosh_conjugate(const ex & x) { // conjugate(cosh(x))==cosh(conjugate(x)) return cosh(x.conjugate()); } Best wishes, Vladimir -- Vladimir V. Kisil email: kisilv@maths.leeds.ac.uk -- www: http://www.maths.leeds.ac.uk/~kisilv/