The Woodbury Identity (identity)

Demo note. This note demonstrates what the SciDraft Hugo theme can do for academic and scientific publishing — for research institutions, researchers and students. Its content is demonstration material only: readers should ignore whether the demo content is correct. The Woodbury identity rewrites the inverse of a matrix plus a low-rank correction in terms of the inverse of the original matrix and a much smaller inverse. It is the algebraic fact behind every method that updates a large system cheaply. ...

September 21, 2026 · 2 min · yourname

Features Are Directions (conjecture)

Demo note. This note demonstrates what the SciDraft Hugo theme can do for academic and scientific publishing — for research institutions, researchers and students. Its content is demonstration material only: readers should ignore whether the demo content is correct. The linear representation hypothesis conjectures that the concepts a network has learned are encoded as directions in activation space, so that adding a concept vector to an activation moves the computation in a meaningful way. ...

September 21, 2026 · 2 min · yourname

The KV Cache Is Exact (claim)

Demo note. This note demonstrates what the SciDraft Hugo theme can do for academic and scientific publishing — for research institutions, researchers and students. Its content is demonstration material only: readers should ignore whether the demo content is correct. Caching keys and values is standard practice, and the claim that justifies it is strong: incremental decoding gives exactly the same outputs as recomputing attention over the whole sequence, not an approximation of them. ...

September 21, 2026 · 2 min · yourname

Attention Variants by Cost and Cache (quadrant chart)

Demo note. This note demonstrates what the SciDraft Hugo theme can do for academic and scientific publishing — for research institutions, researchers and students. Its content is demonstration material only: readers should ignore whether the demo content is correct. Choosing an attention variant is a two-constraint problem rather than a ranking: the score cost decides how long a sequence can be trained on, and the per-token cache decides how long a sequence can be served, and the two orderings of the variants are not the same. ...

September 21, 2026 · 2 min · yourname

A Transformer Training Step (flowchart)

Demo note. This note demonstrates what the SciDraft Hugo theme can do for academic and scientific publishing — for research institutions, researchers and students. Its content is demonstration material only: readers should ignore whether the demo content is correct. One training step is a fixed cycle: the model predicts, the predictions are scored against the targets, the error is propagated backwards, and the parameters move a little in the direction that reduces it. The diagram below shows that cycle; the repetition is the whole of training. ...

September 21, 2026 · 2 min · yourname

Kolmogorov Axioms for a Token Distribution (axiom)

Demo note. This note demonstrates what the SciDraft Hugo theme can do for academic and scientific publishing — for research institutions, researchers and students. Its content is demonstration material only: readers should ignore whether the demo content is correct. An axiom is an assumption taken as given, and the ones that hold up a language model are Kolmogorov’s three: probabilities are non-negative, the whole space has probability one, and disjoint events add. Everything else about token distributions is derived from them rather than assumed. ...

September 21, 2026 · 1 min · yourname

Softmax of Three Scores (example)

Demo note. This note demonstrates what the SciDraft Hugo theme can do for academic and scientific publishing — for research institutions, researchers and students. Its content is demonstration material only: readers should ignore whether the demo content is correct. An example is where a formula stops being notation, and this one is small enough to check by hand: three scores, one softmax, three probabilities that must sum to one. The numbers below are the ones the companion snippet prints, so the arithmetic here and the output of a few lines of code can be compared directly. ...

September 21, 2026 · 1 min · yourname

A Bound on the Attention Output Norm (corollary)

Demo note. This note demonstrates what the SciDraft Hugo theme can do for academic and scientific publishing — for research institutions, researchers and students. Its content is demonstration material only: readers should ignore whether the demo content is correct. Reading a bound off a proposition is the standard use of a corollary, and the one worth having here is a ceiling on how large an attention output can be. Since the output is a convex combination of value vectors, its length can never exceed the longest of them. ...

September 21, 2026 · 2 min · yourname