It is also path-dependent. These divers’ bodies get partly saturated with nitrogen every time they go down, and not all of it goes out of their bodies when they come back up—all of them, sitting around Glory IV playing cards, drinking beer, talking to their girlfriends on their GSM phones, are all outgassing all the time—nitrogen is seeping out of their bodies into the atmosphere, and each one of them knows more or less how much nitrogen’s stuffed into his body at any given moment and understands, in a deep and nearly intuitive way, just exactly how that information propagates through any dive plan that he might be cooking up inside the powerful dive-planning supercomputer that each of these guys apparently carries around in his nitrogen-saturated brain.