slop.boutique

A lab for computation and intelligence as material and medium. Run by Manuel and Ramon.

021 · 23 October 2026 · math · education · handheld

Octavo IDE

An IDE for mathematics chapters on a two-screen handheld: write cards in Markdown and TeX, script verbs and flows, and read, peek, map and practise on the device beside the editor.

Previewin your browser
The two-screen handheld in the Memo swap preset, with Theorem 5.4 moved to the touch screen and marked up in red ink, overlapped by a large render of the Leitfaden map of sheaf theory

In early access for subscribers until 22 November 2026. Subscribe to run it now.

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An IDE for reading mathematics on a two-screen handheld. Each preset is a small chapter written as card files (Markdown with TeX), a little YAML and a main.js; the editor sits beside a working model of the device, and every edit re-runs on its screens.

  • Read on the device: definitions, theorems and proofs typeset in TeX on the top screen; turn pages with L and R, move the cursor onto a term with the D-pad and peek at it with A.
  • A button grammar: X opens an action compass (ask, keep, find, transform), Y asks the tutor, L+R draws the map of the chapter, START opens the contents, SELECT switches the bottom screen between scratch, tutor and notes.
  • Write your own verbs, screens and flows: act.define, ui.view and generator-based flow.define, with an API sheet, an event log and an error list under the editor.
  • Exercises and review: quests with tiered hints, a proof builder whose wrong steps explain themselves, and a recall session graded with the D-pad.
  • Draw on the touch screen: a scratch page with pen, eraser and lasso, and a memo swap that moves the card down to be marked up in red.
  • Tutor: when the app runs on slop.boutique, Claude answers questions about the card or term under the cursor; without it, the tutor answers from text written into the card.

Twenty-five presets come with it, from a guided tour of the buttons and a one-card minimum to chapters on sheaves, compactness and Hausdorff spaces, separation axioms, connectedness, metric equivalence, and categories and functors, plus a Leitfaden of sheaf theory, a Finite Spaces Lab, commutative diagrams from YAML and a blank start.

Octavo Lab, also on this site, uses the same dual-screen handheld for something else: an operating-system playground with programs as QuickJS worlds, fault injection and a coding agent. Octavo IDE is the reading and study side of the device. Typeset with the Latin Modern fonts (GUST Font License), which are embedded in the page.

The full IDE: preset list, the chapter.md card file of the sheaves chapter in the editor, the event log, and the handheld showing Definition 8.3 (Sheaf) on the top screen
The full IDE: preset list, the chapter.md card file of the sheaves chapter in the editor, the event log, and the handheld showing Definition 8.3 (Sheaf) on the top screen
The Leitfaden full size: fourteen ideas in sheaf theory drawn in levels in Latin Modern type, from Topological space and Category down to Sheafification, with Presheaf in red
The Leitfaden full size: fourteen ideas in sheaf theory drawn in levels in Latin Modern type, from Topological space and Category down to Sheafification, with Presheaf in red
The Compactness and Hausdorff preset with spaces.yaml open in the editor and Theorem 5.4 (compact sets in a Hausdorff space are closed) with its proof on the device
The Compactness and Hausdorff preset with spaces.yaml open in the editor and Theorem 5.4 (compact sets in a Hausdorff space are closed) with its proof on the device
The whole handheld during a memo swap: scratch strokes on the top screen, and Theorem 5.4 with its proof on the touch screen, a hypothesis circled and the last line underlined in red
The whole handheld during a memo swap: scratch strokes on the top screen, and Theorem 5.4 with its proof on the touch screen, a hypothesis circled and the last line underlined in red
The Writing a flow preset: main.js defining a quick-check view and a generator flow, the API sheet (content, verbs, screens, furniture, flows, tutor, ink) under the editor, and the question "Is the empty set open in every topology?" on the device
The Writing a flow preset: main.js defining a quick-check view and a generator flow, the API sheet (content, verbs, screens, furniture, flows, tutor, ink) under the editor, and the question "Is the empty set open in every topology?" on the device
Definition 7.1 (Product) full size, with its commutative diagram of T, X, Y and X × Y and the dashed unique arrow
Definition 7.1 (Product) full size, with its commutative diagram of T, X, Y and X × Y and the dashed unique arrow
The action compass open over Definition 8.3 (Sheaf), with ask, flashcard, find, keep and transform around the focused theorem
The action compass open over Definition 8.3 (Sheaf), with ask, flashcard, find, keep and transform around the focused theorem
The handheld with Definition 8.3 (Sheaf) on the top screen and a hand-drawn loop, zigzag and line on the touch screen
The handheld with Definition 8.3 (Sheaf) on the top screen and a hand-drawn loop, zigzag and line on the touch screen
A property table of spaces from spaces.yaml (R, [0,1], Sierpinski space, cofinite N, Q, the Cantor set) against T0, T1, Hausdorff, compact and connected
A property table of spaces from spaces.yaml (R, [0,1], Sierpinski space, cofinite N, Q, the Cantor set) against T0, T1, Hausdorff, compact and connected
Definition 7.3 (Natural transformation) with the naturality square FA, FB, GA, GB
Definition 7.3 (Natural transformation) with the naturality square FA, FB, GA, GB
The proof builder for Theorem 5.3 (compact sets in a Hausdorff space are closed), offering four candidate first steps
The proof builder for Theorem 5.3 (compact sets in a Hausdorff space are closed), offering four candidate first steps
The handheld in the Ink and lasso preset: Definition 8.3 on top and two overlapping loops with squiggles, drawn from code, on the touch screen
The handheld in the Ink and lasso preset: Definition 8.3 on top and two overlapping loops with squiggles, drawn from code, on the touch screen

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