Rename symbols

specification/dartLangSpec.tex

@@ -11718,40 +11718,40 @@ \subsection{Function Expressions}
 \LMHash{}%
 We say that a type $T$
 \IndexCustom{derives a future type}{type!derives a future type}
-$S$ in the following cases:
+as follows:
 
 %% TODO(eernst): Note that `X extends X?` can create an infinite loop.
 %% We will probably make that kind of bound an error.
 \begin{itemize}
 \item
-  %% TODO(eernst): Come mixin classes, extension types: add them.
+  %% TODO(eernst): Come mixin classes and extension types: add them.
   Assume that $T$ is a type which is introduced by
   a class, mixin, or enum declaration.
   If a direct or indirect superinterface
   (\ref{interfaceSuperinterfaces})
   of $T$ is \code{Future<$U$>} for some $U$,
   then $T$ derives the future type \code{Future<$U$>}.
 \item
-  If $T$ is \code{FutureOr<$U$>} for some $U$,
+  If $T$ is the type \code{FutureOr<$U$>} for some $U$,
   then $T$ derives the future type \code{FutureOr<$U$>}.
 \item
-  If $T$ is \code{$T_1$?} for some $T_1$, and
-  $T_1$ derives the future type $S_1$,
-  then $T$ derives the future type \code{$S_1$?}.
+  If $T$ is \code{$S$?} for some $S$, and
+  $S$ derives the future type $F$,
+  then $T$ derives the future type \code{$F$?}.
 \item
   If $T$ is a type variable with bound $B$, and
-  $B$ derives the future type $S$,
-  then $T$ derives the future type $S$.
+  $B$ derives the future type $F$,
+  then $T$ derives the future type $F$.
 \item
-  If $T$ is of the form \code{$X$\,\&\,$B$} then:
+  If $T$ is of the form \code{$X$\,\&\,$S$} then:
   \begin{itemize}
   \item
-    if $B$ derives the future type $S$,
-    then $T$ derives the future type $S$.
+    if $S$ derives the future type $F$,
+    then $T$ derives the future type $F$.
   \item
     if $B$ does not derive a future type,
-    but $X$ derives the future type $S$,
-    then $T$ derives the future type $S$.
+    but $X$ derives the future type $F$,
+    then $T$ derives the future type $F$.
   \end{itemize}
 \end{itemize}