how do I add the last part (**A light can only make 10 transitions**) to this NUSMV code?

Question

QUESTION PICTURE

How do I add the last part (A light can only make 10 transitions)to this code?

MODULE light (other)
VAR

state:{r, y, g};
ASSIGN
init(state) := r;
next (state) := case
        state = r & other =r: {r, y};
        state = y : g;
        state=g : {g, r};
        TRUE : state;
    esac;

MODULE main
VAR
tl1 : process light(tl2.state);
tl2 : process light (tl1.state);