add warning in copy-tree manual

doc/jlatex/jsequences.tex

@@ -396,7 +396,9 @@ \subsection{リスト}
 入れこリストである{\em tree}のコピーを返す。
 しかし、環状参照はできない。環状リストは、
 {\bf copy-object}でコピーできる。
-実際に、{\bf copy-tree}は{\tt (subst t t tree)}と簡単に記述される。}
+実際に、{\bf copy-tree}は{\tt (subst t t tree)}と簡単に記述される。
+なお{\bf copy-tree}は{\em list}しかコピーできず、
+{\em float-vector}などは{\bf copy-seq}を使用しないとコピーできない。}
 
 \funcdesc{mapc}{func arg-list \&rest more-arg-lists}{
 {\em arg-list}や{\em more-arg-lists}それぞれのN番目($N=0,1,\cdots$)の要素からなるリストに

doc/latex/sequences.tex

@@ -393,7 +393,9 @@ \subsection{Lists}
 returns the copy of {\em tree} which may be a nested list
 but cannot have circular reference. Circular lists can be copied by
 {\bf copy-object}.
-Actually, {\bf copy-tree} is simply coded as {\tt (subst t t tree)}.}
+Actually, {\bf copy-tree} is simply coded as {\tt (subst t t tree)}.
+Be careful that {\bf copy-tree} only return the copy of {\em list},
+and you need to use {\bf copy-seq} to copy {\em float-vector} and so on.}
 
 \funcdesc{mapc}{func arg-list \&rest more-arg-lists}{
 applies {\em func} to a list of N-th elements in {\em arg-list} and each of