The definition of the function simp-isreal-p is duplicated. The function is defined in topoly.lisp and in to_poly_solve_extra.lisp. The definitions are identical. At least, with SBCL this gives a warning when loading to_poly_solver. It is not a real problem, but a user might be irritated that something goes wrong when reading the warning from the compiler.
It seems to be no problem to cut out the second definition in to_poly_solve_extra.lisp, because topoly.lisp is loaded first.
By the way, it would be nice to have a separate directory for the code and the documentation for to_poly_solver.