// Solves period for a circular orbit. use systemSolver2.frink symbolicMode[true] orbit= new System[[F === m a, F === G m1 m2 / r^2, a === omega^2 r, freq === omega / (2 pi), period === 1/freq, mplanet === m1, mplanet === m, msun === m2], ["G", "pi"]] println[join["\n",orbit.solveFor["freq"]]] // Plug in values for the earth's mass and its distance from the sun args = [["msun", sunmass], ["r", earthdist]] solutions = orbit.solveForValues["period", args] println[eval[solutions]->"days"]