English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

In the recent years, a number of issues concerning distributions generating1- flags (called also Goursat flags) has been analyzed. Presently similarquestions are discussed as regards distributions generating multi-flags. (Infact, only so-called special multi-flags, to avoid functional moduli.) Inparticular and foremost, special 2-flags of small lengths are a natural groundfor the search of generalizations of theorems established earlier for Goursatobjects. In the present paper we locally classify, in both C{\omega} and C\infty categories, special 2-flags of lengths not exceeding four. We use forthat the known facts about special multi-flags along with fairly recent notionslike strong nilpotency of distributions. In length four there are already 34orbits, the number to be confronted with only 14 singularity classes - basicinvariant sets discovered in 2003. As a common denominator for different partsof the paper, there could serve the fact that only rarely multi-flags' germsare strongly nilpotent, whereas all of them are weakly nilpotent, ornilpotentizable (possessing a local nilpotent basis of sections).

Special 2-flags in lengths not exceeding four: a study in strong nilpotency of distributions