Correct property to count an event until another event happens

In reply to ben@SystemVerilog.us:

Hello Sir,
I have used the Second implication just for checking whether the nested implication works or not.
“until” operator, I used it because I knew that it is being added in the latest LRM and can be used instead of intersecting.
And one more thing is that my code. Is it actually wrong? Because I am not having any error messages on eda playground.