Without that presumption how could anything ever be considered Turing complete? If you're simulating something with infinite memory you get to pretend you have

Without that presumption how could anything ever be considered Turing complete? If you're simulating something with infinite memory you get to pretend you have infinite memory. Feasibility has already been suspended. Edit: ok I get it. Still, GP observation is hardly at that level from my (limited) perspective. Not being able to advance by itself means it's not a standalone system - otoh external actor is obviously implicit for many other examples as well. I suppose they (and me) are taking the word machine too literally. But "pens are Turing-complete" seems a bit, well, diluted.