Repair typo in comment.
diff --git a/Objects/dictobject.c b/Objects/dictobject.c
index 3f77427..b699153 100644
--- a/Objects/dictobject.c
+++ b/Objects/dictobject.c
@@ -1077,7 +1077,7 @@
 	adiff = characterize(a, b, &aval);
 	if (adiff == NULL) {
 		assert(!aval);
-		/* Either an error, or a is a subst with the same length so
+		/* Either an error, or a is a subset with the same length so
 		 * must be equal.
 		 */
 		res = PyErr_Occurred() ? -1 : 0;