A yantra — Lanna nyan (ยันต์) — is a sacred diagram: a grid of syllables, numbers and figures that concentrates protective or auspicious power into a drawable form. Where a katha is the spell spoken, a nyan is the spell inscribed — laid onto cloth, paper, metal foil or skin so that its efficacy stays fixed in an object. The catalogue holds 74 witnesses whose titles name a nyan, and they sit squarely in the wichaa core.
> A note on the name. The corpus writes this as nyan, not yantra — the same > reason the entity was initially invisible to a naive search. Beware, too, that > nyan also transliterates ñāṇa ("insight") in scholastic titles; the match > here is pinned to the diagram sense (nyan lae katha, long nyan, standalone > nyan) to keep the two apart.
The single clearest pattern is that the nyan almost never travels alone: the dominant title-form is "Nyan lae khatha" — yantra and spell — over and over. The drawn diagram and the spoken formula are two halves of one technology, bound in the same volume, and to inscribe a nyan is often literally to "long nyan" — lay the diagram down while reciting its katha. The titles name the varieties by their medium and purpose: Nyan tian luang (the great candle-yantra), Nyan nam bo kaeo (a water-yantra), Nyan pha sahang (a cloth-yantra), and bundles that fold nyan together with holasat, sainyasat and cumnum tewada (assembling the deities). This is the apotropaic heart of the saiyasat in its most concrete, material form.
Like the horā almanac, the nyan is a working object, not an archival one, and its support proves it: 67 mulberry-paper against just 7 palm-leaf. You draw a yantra; you do not inscribe it into a palm-leaf for the library. It is overwhelmingly research-priority — 61 of 74 flagged (82%) — and cuts across the wichaa genres, sitting under astrology (37) as much as magic & ritual (24). It is barely dated (3 witnesses, 1925–1954) — late paper — and it clusters in Nan (27) and Lampang (23), the vernacular working temples, with Wat Sung Men absent entirely.
Corpus — quoted from the contributed printed wichaa textbooks (OCR-digested into the `pages` table), distinct from the palm-leaf catalogue measured above. Citations give slug and page. Where the catalogue shows the nyan as a paper-and- cloth object, the textbooks show it as a system of knowledge with its own teacher-lineage and its own internal argument about legitimacy.
Inference — the textbook framing deepens the catalogue reading: the nyan is not only a material technology (paper, cloth, skin) but a scribal one — a script with a pedagogy, a lineage, and a live debate about where it belongs. The diagram pages in the image store are the artefacts of that script; describing them (below, and in the vision track) is what makes the lek-yant system searchable rather than merely pictured.