Quick patch to avoid LaTeX errors with double subscripts, now that I'm using katex-convert-unicode to convert some characters to LaTeX directly (I should do this only for HTML output… to be fixed later)

katex-convert-unicode.rkt

@@ -23,40 +23,40 @@
   (if (string? str)
       (string-replace*
        str
-       '([₀ "_0"]
+       '([₀ "{}_0"]
-         [₁ "_1"]
+         [₁ "{}_1"]
-         [₂ "_2"]
+         [₂ "{}_2"]
-         [₃ "_3"]
+         [₃ "{}_3"]
-         [₄ "_4"]
+         [₄ "{}_4"]
-         [₅ "_5"]
+         [₅ "{}_5"]
-         [₆ "_6"]
+         [₆ "{}_6"]
-         [₇ "_7"]
+         [₇ "{}_7"]
-         [₈ "_8"]
+         [₈ "{}_8"]
-         [₉ "_9"]
+         [₉ "{}_9"]
-         [ᵢ "_i"]
+         [ᵢ "{}_i"]
-         [ⱼ "_j"]
+         [ⱼ "{}_j"]
-         [ₖ "_k"]
+         [ₖ "{}_k"]
-         [ₗ "_l"]
+         [ₗ "{}_l"]
-         [ₘ "_m"]
+         [ₘ "{}_m"]
-         [ₙ "_n"]
+         [ₙ "{}_n"]
-         [ₒ "_o"]
+         [ₒ "{}_o"]
-         [⁰ "^0"]
+         [⁰ "{}^0"]
-         [¹ "^1"]
+         [¹ "{}^1"]
-         [² "^2"]
+         [² "{}^2"]
-         [³ "^3"]
+         [³ "{}^3"]
-         [⁴ "^4"]
+         [⁴ "{}^4"]
-         [⁵ "^5"]
+         [⁵ "{}^5"]
-         [⁶ "^6"]
+         [⁶ "{}^6"]
-         [⁷ "^7"]
+         [⁷ "{}^7"]
-         [⁸ "^8"]
+         [⁸ "{}^8"]
-         [⁹ "^9"]
+         [⁹ "{}^9"]
-         [ⁱ "^i"]
+         [ⁱ "{}^i"]
-         [ʲ "^j"]
+         [ʲ "{}^j"]
-         [ᵏ "^k"]
+         [ᵏ "{}^k"]
-         [ˡ "^l"]
+         [ˡ "{}^l"]
-         [ᵐ "^m"]
+         [ᵐ "{}^m"]
-         [ⁿ "^n"]
+         [ⁿ "{}^n"]
-         [ᵒ "^o"]
+         [ᵒ "{}^o"]
          [⊆ "\\subseteq" "\\ensuremath{\\subseteq}"]
          [⊂ "\\subset" "\\ensuremath{\\subset}"]
          [⊇ "\\supseteq" "\\ensuremath{\\supseteq}"]