in which they "show" that different layers can be formed simultaneously.
That they can be formed simultaneously? wow, i'd like to hear that explanation.
I'm sure it's something stupid like:
"well logically we can compare this to a sandwich. First you put the Salami, then cheese, then tomato and finally the lettuce. But sometimes, you can just drop all of them at the same time on the bun. So there you go, layers can be formed simultaneously".