[temp.over.link] Reword to clarify that declarations correspond (#5999)

Author: tkoeppe

source/templates.tex

@@ -3908,15 +3908,19 @@
 whether two constructs are equivalent, and they are
 functionally equivalent but not equivalent, the program is ill-formed,
 no diagnostic required.
-% FIXME: What does it mean for two function templates to correspond?
-Furthermore, if two function templates that do not correspond
+Furthermore, if two declarations $A$ and $B$ of function templates
 \begin{itemize}
-\item have the same name,
-\item have corresponding signatures\iref{basic.scope.scope},
-\item would declare the same entity\iref{basic.link} considering them to correspond, and
-% FIXME: What does it mean for a set of template argument lists to satisfy a function template?
-\item accept and are satisfied by the same set of template argument lists,
+\item
+introduce the same name,
+\item
+have corresponding signatures\iref{basic.scope.scope},
+\item
+would declare the same entity,
+when considering $A$ and $B$ to correspond in that determination\iref{basic.link}, and
+\item
+accept and are satisfied by the same set of template argument lists,
 \end{itemize}
+but do not correspond,
 the program is ill-formed, no diagnostic required.
 
 \pnum