Line of control between a type and their functions

Those are definitions though @ash.

And as Peterson would say, "and fair enough!"

And I'll throw in, "jolly good show!"

Do you have any examples?

With people in them?

Well, the auxiliary or instrumental is after all like a tool, so utilitarian in essence. It's 'creative' in that it births something, kind of like forceps.

The agenda or the mission is that which is born and what is born can't really be subject to parent's or doctor's control for too long.

But the way I see it, once this is understood then the third can really plunge into the fourth and then you're playing with a full deck, even if it's bound to be stacked.

@ash , I think the second row is usually the one that is 'most intact', both orientations are used (except in case of extreme jumpers where sixth is highly preferred so that second may remain underdeveloped).

I think the use of extraverted functions amplifies other extraverted functions and likewise introverted implies introverted, so when someone really starts to unignore the fifth or access the fourth, the fifth and the fourth encourage each other's development, so that will happen more or less simultaneously at average health.

I think the problem is that people get caught up in the sixth as a stress movement. The sixth is the other end of the axis of the PolR. If the fourth is accessed in such a way that it threatens the PolR, there will be a compensatory overuse of the sixth to protect the seventh.

This will stymie the entire process of development. This is what we're seeing with Barby in the Israel video. He did very well accessing his inferior Fi fourth because he knew he had to with the 'very touchy subject', but it threatened his vulnerable Ni seventh. He likes to travel light, TeSi itself uses a 'lego toy' approach to fitting things together. He could sustain quite a bit of Fi but not so much that it would force him into 'nonlinear' vortex meaning Ni (which is centripetal rather than centrifugal Ne, his third). So he overcompensated with stress movement to demonstrative sixth Se and got stuck there.

Even his Ti got weaker, his Fi got formulaic (peacocky), his Si got more piecemeal, nothing really developed despite the potential, but his vulnerable stayed safe.

Use of sixth to 'demonstrate' happens all the time. And because it 'demonstrates', yes, it gives birth to something in the world.When it's a stress movement that becomes prolonged, the whole process is arrested.  

Yes, many people see sixth as something like 'uber-tertiary' and that's why they call it 'shadow agenda'. But I see 'stress movement to sixth' as just that, a stress movement, and its main purpose as protecting the vulnerable function. Sixth stress movement doesn't birth anything; it's more like an abortion to "protect" the mother.

TeSi is very good to look at because it's itself so workmanly. The processes going on may be laid out quite clearly.

What we have been seeing is that the TeSi 'gurus' who are routinely exposed to materials that previously were 'hermetic' are using them in a workmanly fashion with massive Se stress amplification to protect the vulnerable Ni  (because the esoteric materials they work with are, or should be, Ni). So what we get are very big blowhards with massive posturings of greatness. 

Barby isn't one of those because he's not in such a field, but it's interesting and illustrative to see the parallels with him.

Well it does serve an evolutionary purpose. You can't sit in class and diligently focus on what's being taught whilst neglecting the fact you're having a heart attack.