Thanks alot for your response, your notes did solve my issue, I just have a few questions left here.
Why did you add (k+1) to your problem in - int2d(Th)((k+1)*(x+y)*vh); ? because I don’t want number of my mesh changes my equation.
I would like to explore more about the methods that you proposed to me, like changing names “mesh”+k+".msh" scripts , or defining folders system(“FreeFem++ main(k+1).edp”); May you introduce more examples or training on the freefem tutorials website so that I can read? I couldn’t find it myself.
My other question is that do you know how can I use shell scripting for this problem?