Theorem Design Language
Specifications for the constructed turnstile mark (⊢), color tokens, typography scales, and media kit for contributors and partners.
The Constructed Turnstile (⊢)
The mark is a constructed turnstile (⊢) — the formal logical notation for "derives" or "therefore." A theorem is a statement derived from axioms through valid steps. The symbol that proof theory uses for "derives" is the same symbol that names the product. The mark is never the literal Unicode character; it is always authored from exact vector geometry.
Mark Anatomy & Strict Geometry
| Vertical bar width | 12.5% of mark height |
| Horizontal midbar weight | Same as vertical bar |
| Midbar vertical position | 44% from top (not centered) |
| Midbar length | 62% of total width |
| Minimum rendered size | 14px tall |
| Clear space zone | 1× mark height minimum |
Note on Midbar Position: Centering the midbar vertically causes the shape to visually read as an uppercase letter "F" rather than a formal logic symbol. The 44% offset preserves its mathematical character.
- Always render "Theorem" at weight 300 (light).
- Always maintain 1× mark height clear space on all four sides.
- Credit the umbrella institution as
fundaments.workin mono uppercase. - Use the 6-color taxonomy for all highlight interfaces.
- Never round corners on UI chrome, controls, or mark bars (radius is 0px).
- Never rotate, slant, skew, or outline the mark.
- Never bold the wordmark for emphasis (use scale, not weight).
- Never place on noisy photographs or multicolored gradients.
6-Color Semantic Taxonomy
Theorem defines an explicit semantic meaning for each highlight color so exported Markdown notes carry uniform cognitive significance across Obsidian, Logseq, and external tools.
Badges for Obsidian Plugins & Ebook Repos
[](https://theorem.fundaments.work)
[](https://theorem.fundaments.work)
Download Vector Brand Master Pack
Official SVGs for the Turnstile Mark [⊢], app icon, horizontal lockup, and badges.