[unord.req] Clarify what r1 is and remove unnecessary variable e.

Author: zygoloid

source/containers.tex

@@ -2285,12 +2285,11 @@
 \item \tcode{eq} denotes a possibly const value of type \tcode{key_equal},
 \item \tcode{ke} is a value such that
   \begin{itemize}
-  \item \tcode{eq(r1, ke) == eq(ke, r1)} with
-    \tcode{r1} the key value of \tcode{e} and \tcode{e} in \tcode{a_tran},
+  \item \tcode{eq(r1, ke) == eq(ke, r1)}
   \item \tcode{hf(r1) == hf(ke)} if \tcode{eq(r1, ke)} is \tcode{true}, and
   \item \tcode{(eq(r1, ke) \&\& eq(r1, r2)) == eq(r2, ke)}
   \end{itemize}
-  where \tcode{r2} is the key of an element in \tcode{a_tran},
+  where \tcode{r1} and \tcode{r2} are keys of elements in \tcode{a_tran},
 \item \tcode{n} denotes a value of type \tcode{size_type},
 \item \tcode{z} denotes a value of type \tcode{float}, and
 \item \tcode{nh} denotes a non-const rvalue of type \tcode{X::node_type}.