`SSG/Html.lean`

Explanation legend Lean4 Domain Explanation Language (L4DEL)

L4DEL explanations are a separate layer. They do not change the Lean source. Intuition is explanatory prose; numbered items are a reading path; sources link the wording back to evidence.

L4DEL: Lean4 Domain Explanation Language

Annotation provenance. This overlay contains 8 curated AI-written annotations and 3305 mechanical source-derived annotations. They have not been human-reviewed as explanations; treat them as unverified and not mathematical authority. Retained generation history: The 71 original curated annotations were produced in a Claude Sonnet 5.5 session at medium effort; Claude Opus 5.5 is recorded in that session as the advisor model, not the direct author. The bulk source-derived expansion was generated mechanically from pinned source comments by tooling developed in a GPT-5.6 Sol session at ultra reasoning; GPT-5.6 Sol did not originate the quoted source prose. On 2026-10-17 the mechanically generated source-comment annotations of the Formal Conjectures, Carleson, FLT, PFR, CompFiles, Mathematics in Lean and Theorem Proving in Lean overlays were regenerated by the same generator after three corrections made in a Claude Sonnet 5.5 session: titles no longer cut a sentence inside mathematics or end on a dangling word, workflow markers are removed from the quoted prose, and declaration names follow the scanner's namespace resolution. The boilerplate step line was dropped, and comments that were only a row of dashes no longer yield annotations. No new prose was written and no human review is claimed.

Credit: The upstream authors and contributors retain credit for the project and mathematics. lean4-explainer only renders their pinned source and adds the separately disclosed explanation layer.

Project sources: Pinned compfiles documentation, Pinned compfiles corpus index

7 declarations, 0 contain sorry, 0 declared as axioms

Imports (1)

SSG.Util

Imported by 14 files

abbrev Attr A single HTML attribute line 8 source
Source documentation
A single HTML attribute
```
abbrev Attr := String × String
```
inductive Html HTML document tree line 11 source
Source documentation
HTML document tree. Structural correctness by construction.
```
inductive Html where
…
```

def Html.render Render to string line 27 source

Source documentation

Render to string

partial def render : Html → String
| .raw s => s
| .text s => htmlEscape s
| .void tag attrs => s!"<{tag}{renderAttrs attrs}>"
| .elem tag attrs children =>
  let inner := String.join (children.map render)
…

Mentions: Html, htmlEscape

def Html.renderDoc Render a full HTML5 document with doctype line 40 source
Source documentation
Render a full HTML5 document with doctype
```
def renderDoc (h : Html) : String :=
…
```
Mentions: h, Html
instance Html.(instance at line 43) line 43 source
instance Html.(instance at line 46) line 46 source
instance Html.(instance at line 49) line 49 source