Look at flag --standalone. At least for html output pandoc seems to be able to handle something that feels like partial pandoc input in practice and produce html output that behaves like a snippet.
Pandoc AST - format called "native" - parses faster than pandoc markdown.
Trigonometric polynomials are also polynomials. And linear spaces are all "the same". That is what the definition is for. Even the transpose-mapping is linear.
Probably busy doing data processing at any given moment.