sol := dsolve([op(eqs), op(ICs)], numeric, range = 0 .. tmax, abserr = 10^(-3), relerr = 10^(-3), stiff = true, maxfun = 0);
Error, (in dsolve/numeric/process_input) system must be entered as a set/list of expressions/equations
can any one tell how to remove this error?