I'm sorry not to have provided more information in my first e-mail although i'm very glad so many people responded to help, but i've done some more testing:
specifically i'm getting 'prase error in tmp/x' where x is a long string of characters that tends to change on every run of the complier (at least when i'm compiling other programs). I've tried the following and gotten no errors #include <stdio.h> #include <math.h> double num=16.0; int main() { double sqrt(double num); return(0); } the following warns me that 'function sqrt does not match global variable' but still compiles #include <stdio.h> #include <math.h> float num; int main() { float sqrt(float num); return(0); } and this one just doesn't work at all giving the parse error previously described: #include <stdio.h> #include <math.h> double num; int main() { num = 16; /*i've also tried 16. and 16.0 here*/ double sqrt(double num); return(0); } I'm sorry I was not more clear with my first e-mail and hope this points out the problem better. Also, how do I let gcc know that I want math.h to be an available library so i dont' have to use the -l option every time if run it? one final thing: did any of you try comiling the non-working examples on your gcc's? did you get any errors? thanks a lot