Hi there, basically, EASY is a cycle - eat, activity, sleep - that gets repeated throughout the day in the same order. However, when people on here talk about A times, they mean everything from when baby wakes to when they go back to sleep for the next nap, including eating.
A 30-minute nap can often mean that a baby is overtired. Have you tried to resettle him at all when he wakes? Any luck? Perhaps you could try putting him down a little earlier to see if that helps. Of course, if the nap is still short, you may end up with something more like EASAE, followed by a very short A time. Don't worry too much - keep it calm and consistent and he'll get it eventually!
I hope that helps? Good luck