Dear Art, I hope you do not mind the significant delay in my response. On Wed, Jan 26, 2005 at 05:45:34PM -0800, Art Vanden Berg wrote: "[..] As things turned out, the only onboard software bug that caused any problem was a single case of forgetting to use fabs(float) in one conditional line. [..]" Just one bug in C is impressive. Congratulations. As for would this have happened in Ada?: a positive real data type could have been used such that forgetting to get its absolute value would not have been an issue: but perhaps you would have forgotten to declare such a type (however, if you needed to use fabs() more than once, then there is already a bonus in simply declaring positive floating point numbers without having to remember to apply the absolute conversion logic every time), but depending on your needs perhaps a negative real value was meaningful for the variable in your bug in other parts of the code in which case you might not have been so lucky that a compile time error message would have saved you instead of a runtime problem with C, but it depends. Regards, Colin Paul