diff --git a/data/abbreviations.json b/data/abbreviations.json
index a839ba7..c41a55d 100644
--- a/data/abbreviations.json
+++ b/data/abbreviations.json
@@ -429,6 +429,8 @@
   "to_s": "→ₛ",
   "r_s": "→ₛ",
   "simplefunc": "→ₛ",
+  "heyting": "⇨",
+  "himp": "⇨",
   "covers": "⋖",
   "covby": "⋖",
   "wcovby": "⩿",