MULTIPLICITIES _ _ _ _ _ _ _ _ _ _ _ _ switch
When solve is applied to a set of equations with multiple r oots, solution multiplicities are normally stored in the global variable root_multiplicities rather than the solution list. If you want the multiplicities explicitly displayed, the switch multiplicities should be turned on. In this case, root_multiplicities has no value.
solve(x^2=2x-1,x); X=1 root_multiplicities; 2 on multiplicities; solve(x^2=2x-1,x); X=1,X=1 root_multiplicities;