 { $subsection virtual@ } ;
 
 ARTICLE: "virtual-sequences" "Virtual sequences"
-"Virtual sequences allow different ways of accessing a sequence without having to create a new sequence or a new data structure altogether. To do this, they translate the virtual index into a normal index into an underlying sequence using the " { $link "sequences-virtual-protocol" } "." ;
+"Virtual sequences allow different ways of accessing a sequence without having to create a new sequence or a new data structure altogether. To do this, they translate the virtual index into a normal index into an underlying sequence using the " { $link "virtual-sequences-protocol" } "."
+$nl
+"One current limitation of the virtual sequence protocol is that sequences must be indexed starting at zero." ;
 
 ARTICLE: "sequences-integers" "Integer sequences and counted loops"
 "Integers support the sequence protocol in a trivial fashion; a non-negative integer presents its non-negative predecessors as elements. For example, the integer 3, when viewed as a sequence, contains the elements 0, 1, and 2. This is very useful for performing counted loops."

{ $subsection new-resizable }
{ $see-also "sequences-unsafe" } ;

ARTICLE: "sequences-virtual-protocol" "Virtual sequence protocol"
"Virtual sequences must know their length:"
{ $subsection length }
"The underlying sequence to look up a value in:"


HELP: nths
{ $values
     { "indices" sequence } { "seq" sequence }
     { "seq'" sequence } }
{ $description "Ouptuts a sequence of elements from the input sequence indexed by the indices." }
{ $examples 
