Avoid nested dollar math.

Eelis · Eelis · commit 7eaad29c229e · 2023-01-04T18:31:03.000+01:00
Because cxxdraft-htmlgen does not support it.
diff --git a/source/containers.tex b/source/containers.tex
@@ -18255,7 +18255,7 @@
 
 \pnum
 An integer $r$ is a \defn{rank index} of an index space $S$
-if $r$ is in the range $[0, \text{rank of $S$})$.
+if $r$ is in the range $[0, \text{rank of }S)$.
 
 \pnum
 A pack of integers \tcode{idx} is
