@Markiyan Hirnyk 

Thank you for reminding me of the description of Modular subpackage. I got it!!

Thanks a ton for your code. I do appeciate your kindness. I'll try it ASAP. Actually, solving the series of system is one step of my algorithm and the timing is not satisfactory. Therefore, I wanna know if parallel computing can help me.  So, please show me the parallel code if it's not too much bother.

Thanks a ton for your code. I do appeciate your kindness. I'll try it ASAP. Actually, solving the series of system is one step of my algorithm and the timing is not satisfactory. Therefore, I wanna know if parallel computing can help me.  So, please show me the parallel code if it's not too much bother.

@Carl Love 

Yes, a finite field of integers, and the modulus is less than 2^64.

@Carl Love 

Thanks for your so quick reply! Yes, A is dense and n is less than or equal to 100. Everything works in finite field. Longing for your reply.