Correct a typo about closurization

specification/dartLangSpec.tex

@@ -15274,7 +15274,7 @@ \subsubsection{Instance Method Closurization}
 \LMHash{}%
 Otherwise $T$ is a generic instantiation of a generic class $G$.
 Let $X''_1, \ldots, X''_{s''}$ be the formal type parameters of $G$,
-and $t''_1, \ldots, t''_{s''}$ be the actual type arguments of $o$ at $T$.
+and $t''_1, \ldots, t''_{s''}$ be the actual type arguments of $o$ at $G$.
 Then $T_j$ is a type annotation that denotes
 $[t''_1/X''_1, \ldots, t''_{s''}/X''_{s''}]S_j$,
 where $S_j$ is the type annotation of the corresponding parameter in $D$.
@@ -15438,7 +15438,7 @@ \subsubsection{Super Closurization}
 \LMHash{}%
 Otherwise $S$ is a generic instantiation of a generic class $G$.
 Let $X''_1, \ldots, X''_{s''}$ be the formal type parameters of $G$,
-and $t''_1, \ldots, t''_{s''}$ be the actual type arguments of $o$ at $S$.
+and $t''_1, \ldots, t''_{s''}$ be the actual type arguments of $o$ at $G$.
 Then $T_j$ is a type annotation that denotes
 $[t''_1/X''_1, \ldots, t''_{s''}/X''_{s''}]S_j$,
 where $S_j$ is the type annotation of the corresponding parameter in $D$.