[tuple.creation] Remove unused introductory notation

Author: JohelEGP

source/utilities.tex

@@ -1878,11 +1878,6 @@
 
 \rSec2[tuple.creation]{Tuple creation functions}
 
-\pnum
-In the function descriptions that follow, the members of a template parameter pack \tcode{\placeholder{X}Types}
-are denoted by \tcode{\placeholder{X}}$_i$ for $i$ in \range{0}{sizeof...(\placeholder{X}Types)} in
-order, where indexing is zero-based.
-
 \indexlibraryglobal{make_tuple}%
 \indexlibrarymember{tuple}{make_tuple}%
 \begin{itemdecl}