I agree with several things, like when you said that Pi is a system. Yes, it's a system that works in a certain way (Dynamic) but it's not actually running or tested (Introverted) - this is where the moment you use such function, you're perceiving
things, you're trying to figure out something.
Example: a red button. Not the button itself, but its functionality, it is inherently a such Pi system, it is Dynamic Fields - just the functionality, but no current or past action that someone can refer at (that would be Bodies).
Now, ask a Si Irrational to tell you what's gonna or what's likely to happen when that button is pressed. He/she will look dumb at you and say that he doesn't know. A similar experiment revealed that Capitalist Pig
is SLI to me. Si doesn't deal with mental associations, "possibly", "likely", "maybe", because it's External - it needs hard support to process, in general it needs to experience anything. It is a fact that SXIs don't guess
, that they naturally don't even try to, you may try this on SXI people that you correctly typed - this is a type-related trait that I'm most certain of.
Ni types, however, immediately start to think, to guess what's that about, to imagine the scenario and find similarities with what they know and clues on what possibilities could there be.
But that's not all. The whole question, apparently the whole issue is dealt with as a red button. The SLI will think that you could maybe tell what's going to happen if you're there, that there are certainly physical clues, he will think about something real although it's a hypothetical situation, while the ILI begins by trying to figure out what's the point of the question in the first place, what's going to happen if he answers or depending on what he answers, even rambling and entering mental games. (these make part of my observations and tests IRL)
(Note that I observed differences between when you specify that you'll ask a test question and it's spontaneous, you just ask that out of the void "say that there's a red button...". It also may depend on the person who asks, as usually such test is not bullet-proof - in general, if you know what to expect from this person and it matches one of the two patterns above, you can pick among Ni and Si easily, if applicable.)