"I'll get on that now."

Walking towards the cave entrance she spots Nico, smoothing out the floor by rolling stalagmites into big stone spheres. Some older kids -eight to twelve or so- are playing on a few he lined up in a little depression at the edge of the cave.

Awww, cute. She finds a quiet spot where she's reachable but out of the way and pokes at the mentalism side of things. What are the primitive actions of this shiny new magical skill, and can she store data or procedures in the core?

The Core is... Weird. There's a bunch of ways she could interact with it but to her magic senses it's a bright-hot ball of energy, unclaimable, but a source of infinite imbuement.

The primitive actions of mentalism are remembering, math, and deciding. Also, telekinesis. She could, for example, make a rock that hovers after it's touched five times. Or a door that only opens if you tap the right pattern. Or a todo list in her head. Or a tray that floats if someone is touching it. She could also make an Excel spreadsheet if she's willing to recharge every cell manually and give up on advanced formulae like vlookup for now.

Oh wow. She basically has magical programming. Nico said as much but it's cool to just feel it. Does it provide any straightforward way to share data storage between her and Nico without needing a physical object to bind the data to? Does it come with loop primatives, or just if/elseif/else? 

Her magic instincts seem pretty sure that data storage requires a mentalism-binding (what Nico called an idea), and those need to be anchored to something physical. A loop is not a primitive but it's pretty obvious how to put it together with ifs and counting.

Yeah, building up the rest of the language from ifs and variables is doable. Does referencing a stored procedure in another idea seem doable? Or at least stored procedures in one large idea?

Yes, you can make ideas ... not arbitrarily complicated, but pretty complicated before running into issues. And combine that with telekinesis flipping switches and activating or deactivating things and you can get pretty creative.

Progress. What about power transfer, can she power it centrally and have power distributed to subsystems?

Oh, you need wire for that. Gold works best, but anything electrically conductive can carry imbuement.

Yeah, she's definitely making a computer when she's got spare time. How about a to-do list in her head for now, she'll get more elaborate later.

She can put formatted text into an idea and anchor it to her fingernail or wherever else, easy peasy.

Then in goes the to-do list, and then up she gets to see how everyone's doing. Anyone looking for her but being shy about it?

Most people seem to be winding down for sleep. Mr. Cooper has found a bedroll going spare and its former owner- A youngish woman with a spear and short green hair, wearing leather armor- Makes sure to follow along, apologizing for how ratty and old it is. But it kept her warm on patrol faithfully for years and years, so it ought to be solid.

"Thank you very kindly. I don't need much, just something soft and warm through the night. This will do nicely. What's your name?"

"Rama, milady."

She smiles softly and shakes her head. "Good to meet you, Rama. I'm Sable. All this 'milady' stuff will make it a pain to make actual friends, though. Do most binders demand things like that?"

She visibly relaxes, and smiles. "Well, it's a poor idea not to at first, isn't it? And most of us have never so much as seen a binder in person. Old demesnes are big and crowded."

She giggles and shakes her head. "I'm just an ordinary — if somewhat weird — girl with a job that comes with a lot of responsibility. Just trying to do right by people and help make a home for all of us, y'know? I can understand the precaution, though. Better to be too deferential than to piss off someone who can turn you inside out."

She frowns. (Mr. Cooper turns to head back to his tallying.)

"Well, we're going to be deferential, I think. It's just how it's done. I was sure hoping it'd be Donovan but if hopes were ropes, I'd be able to make a fishing net."

She frowns sadly. "I wish I could've met him. From what little I've heard, it sounds like people respected him."

"Well... That's kind of life. I'm gonna end up in the pyre some day too, either by some dragonborn abomination or the march of time, so I try to enjoy life while it lasts. Speaking of which, I hope you two arrange some hot baths with your infinite binder magic at some point."

"Oh goodness yes. That's absolutely essential, sooner or later. We've gotta have our hot baths. Most of that will be on Nico as our whisperer, making the baths and the hot water, but now you've got me brainstorming some kind of soap plant that smells really nice. Maybe even see if I can manage to add a relaxation effect, for after a long day of work."

Soap plants and hot baths go into the to-do list.

"There's gonna be tons of challenges... And houses for everyone, and everything else... Honestly, you kind of expect the binders to be lazy and get other people to do most of the work? But whatever other people can do to make your jobs easier, we oughta. It's just efficient."

"I mean, division of labor is good, and people should focus on their comparative advantage, but if I'm not putting in a full day of magic work then I should find something useful to do with my time."

"Well, dungeon binders' comparative advantage is magic, is what I'm saying. 'Comparative'- Sound like I'm back in finishing school*, heh."

*Not a literal translation, but the closest available cultural referent.