Re: Terms: I.S., I.P., Neijin, Fajin, Aiki, etc.
"AiKi" implies a 'mixing of ki-strength' or a 'mixing of ki'. All strength and movement comes from ki in the body (which is interrelated with fascial strength), so a weight lifter can have 'strong ki', but he may not be able to manipulate that ki in the optimal way with his hara/middle/dantien. So if the aforementioned weight-lifter attacks someone who is skilled in 'internal strenght', there could be a mixing of forces which in turn defeats the weight-lifter. Hence, "Ai Ki".
I think this definition of Aiki is not in alignment with what most of those who practice Aikido would call Aiki.