cat / diagramzip
clone

a browser-first diagram editor with live svg previews, local drafts and encrypted, accountless sharing

main
diagramzip / skills / set-diagram / SKILL.md
SKILL.md 2.1K source

name: set-diagram description: Use when the user needs to show membership, overlap, exclusion, union, intersection, or nested categories with sets.

Set diagram

What / why

A set diagram tells the story “which elements belong to which sets, and where do memberships overlap?” Use Venn diagrams for a small number of sets and Euler diagrams when only meaningful intersections should be shown. Choose a graph for typed relationships or a matrix for exhaustive pairwise comparison.

How to model

  • Define each set and the universe or scope; state whether circles are exhaustive.
  • Put elements in regions only when membership is known; distinguish empty from unknown.
  • Label intersections with the set operation or plain-language meaning.
  • Keep set count small enough for legible regions; use an Euler representation for sparse overlaps.
  • Do not use area or circle size to imply quantity unless it is quantitatively encoded and explained.

Styling and customization

Use overlapping outlines with high-contrast labels, transparent fills, and patterns or labels in addition to color. Avoid excessive intersections. Provide an accessible list/table of memberships when important, and keep the universe boundary visible when it matters.

Renderer choices

Preserve user choice. Mermaid, Graphviz, D2, PlantUML, and diagrams.net can approximate set diagrams with shapes and labels; diagrams.net or custom SVG is better for controlled overlap. diagram.zip has no dedicated Venn/Euler semantic renderer or overlap solver, so verify memberships manually and do not claim proportional geometry.

Review

Check every region against membership data, confirm empty/unknown regions, make labels readable, and test grayscale/colorblind viewing. Ensure the chosen Venn layout can represent stated intersections; otherwise switch to Euler or a table.

Prior art and gaps

See references/prior-art.md. A native set renderer would need membership input, Venn/Euler layout validation, and an accessible tabular fallback; this is an integration opportunity rather than current diagram.zip support.