select_process: process(pr_state, sens)
begin
case pr_state is
    when state0 =>
        if sens(0)='1' then
            pr_state<=state1;
        else if sens(1)='1' then
            pr_state<=state4;
        end if;

    when state1 =>
        if sens(1)='1' then
            if sens(0)='1' then
                pr_state<=state2;
            else if sens(0)='0' then
                pr_state<=state3;
            end if;
        end if;

    when state4 =>
        if sens(0)='1' then
            if sens(1)='1' then
                pr_state<=state5;
            else if sens(1)='0' then
                pr_state<=state6;
            end if;
        end if;

    when state2 =>
        if sens(1)='0' then
            pr_state<=state0;
        end if;

    when state3 =>
        if sens(1)='0' then
            pr_state<=state0;
        end if;

    when state5 =>
        if sens(0)='0' then
            pr_state<=state0;
        end if;

    when state6 =>
        if sens(0)='0' then
            pr_state<=state0;
        end if;
end case;
end process;