Hello everybody I'm new to GiNaC. I'm trying to use it to solve linear algebraic system of equations and running the example from the tutorial https://www.ginac.de/tutorial/Solving-linear-systems-of-equations.html#Solvi... symbol a("a"), b("b"), x("x"), y("y"); lst eqns, vars; eqns = a*x+b*y==3, x-y==b; vars = x, y; cout << lsolve(eqns, vars) << endl; While it works perfectly when I run it several times I get different solutions (they are all equivalent though). For example: {x==(3+b^2)*(a+b)^(-1),y==-(a+b)^(-1)*(-3+a*b)} or {x==(b+a)^(-1)*(3+b^2),y==-(-3+b*a)*(b+a)^(-1)} what is going on there? Is there a way to have a deterministic solution? Thanks in advance. Fede -- I find television very educational. Every time someone switches it on, I go into another room and read a good book.