Because the state 2+ is defined only as ' no claim made the previous year'. Any claim from state 3 will result into a transition to state 2- The sole purpose of dividing the states was to specify a different state that deals only with 'a claim in the previous year', which is 2-. 2+ will only be achieved when one doesn't claim from state 1. Hence, transition from 3 to 2+ is not possible.
