AK HOLDING

TECHNOLOGY

AK Holding d.o.o. · Ciril-Metodov trg 12 · 1000 Ljubljana · Slovenia

We build one thing at a time. At the moment that thing is Vsota — a cross-sums puzzle where every answer is reasoned, never guessed.

The app

Vsota

A grid of short runs — a few empty cells in a row or a column — and each run carries one number: the total its digits have to make. Digits one to nine, none repeated inside a run. From that alone the whole board can be worked out.

Every cell sits in two runs at once, one across and one down, and that is where the puzzle stops being arithmetic and starts being logic. A total narrows a run to a handful of possible digit sets; the run crossing it narrows them again; keep going and the grid closes on its single answer. Every board has exactly one solution and none of them needs a guess.

Packagecom.stevilke.vsota
LanguagesSlovenian and English
ConnectivityFully offline · no account · no advertising
PublisherAK Holding d.o.o., Ljubljana, Slovenia
An experiment with the rules

What is a clue actually worth?

Not how to use one — how much of the work one clue can possibly do, measured in bits, before any crossing is looked at.

A run of k cells can hold any of C(9, k) digit sets. Reading its total rules most of them out, and what is left is the uncertainty the clue could not remove. The gap between the two, in base-two logarithms, is the information the clue carried. Averaging that over the clues you actually meet gives a single number per run length — and the shape of that number across lengths is not what anyone expects.

Digit sets a run of this length can hold126
Different totals a clue of this length can show21
Sets still standing once you have read the clue8.49
What one clue is worth3.89 bits
Clues that leave exactly one set standing3.17%
Cells on a board of that many runs80
61% FROM CLUES

Pinning every cell on this board takes 253.6 bits. All 40 clues together supply 155.6 of them. The remaining 97.9 bits are nowhere on the board — they come out of the crossings, from the fact that every cell has to satisfy two runs at once.

Bits per clue, by run length

The curve is almost flat. A two-cell clue is worth 3.64 bits, a seven-cell clue 3.64, and the best a clue ever manages is 3.89 bits — while the set it has to pin down needs up to 6.98. Then comes the collapse: a nine-cell run must use every digit once, so its total is always 45 and the clue tells you nothing at all. Vsota's difficulty was never in the sums. It is in everything the clues leave over.

Not here: no board, no table of totals and digit sets, no list of which sums force which digits, nothing that shortens a puzzle. This measures the rules from the outside. Solving one is the other thing.

A word about the name

“Holding” describes a company, not an offer

AK Holding d.o.o. is a Slovenian limited company, and the word in its name says how it is organised — nothing more. No security, fund, deposit, loan, brokerage or investment advice is offered on this page or inside the app, and nothing here should be taken as any of those. The only sums involved are the ones printed on the puzzle.

Get in touch

One mailbox, read by a person

Bug reports, a board that behaves oddly, a question about what the app keeps — all of it goes to klik@systempoint.rest. What Vsota stores, and what it does not, is set out on its Privacy Policy page.