v6.1.2

Fixed

• The reachable-pair count columns of the graph tables were inconsistently
  named (e.g. grammar on the biological_uniprot page, bare grammar names
  on the rdf page); they are now uniformly Reachable pairs, with the rdf
  page's per-grammar columns prefixed Reachable pairs / <grammar> (#169).
• The field-sensitive-alias pages rendered the edge label f_r_i as a TeX
  double subscript, which MathJax rejects with "Double subscripts: use
  braces to clarify" (#173); the label is now f_{r\_i} in the ten
  per-graph Edges Statistics tables and the canonical-grammar block.
• Seven grammar pages used & alignment tabs in plain display math, which
  MathJax rejects with "Misplaced &" (#174); the blocks are now wrapped in
  \begin{aligned} ... \end{aligned}.
• The eclass graph page's Source link (and the historical old_graphs
  page's Origin link) pointed to a URL the hosting university removed from
  its site; they now point to the archived original (Wayback Machine
  snapshot of the eClassOWL 5.1.4 ontology file the original page
  redirected to).

Changed

• The math-snippet guard now validates every docs-page and package-docstring
  math snippet with the MathJax engine itself (mathjax 4.1.3 on Node,
  utils/check_math_snippets_node.cjs) instead of hand-crafted patterns,
  reporting the engine's own error message; the browser bundle is pinned to
  the same version (mathjax_js in docs/conf.py), and the guard also runs
  as a pre-commit hook.