     }
 }
 { $errors "Throws an error if the index is out of bounds." } ;
+
+HELP: index-to-tail
+{ $values
+    { "seq" sequence } { "from" integer }
+    { "length" object }
+}
+{ $description "Sets up the stack for the " { $link tail } " word." } ;
 
 HELP: tail
 { $values { "seq" sequence } { "n" "a non-negative integer" } { "tailseq" "a new sequence" } }

    }
} ;

HELP: slice
{ $class-description "A virtual sequence which presents a subrange of the elements of an underlying sequence. New instances can be created by calling " { $link <slice> } ". Convenience words are also provided for creating slices where one endpoint is the start or end of the sequence; see " { $link "sequences-slices" } " for a list."
$nl

HELP: infimum
{ $values { "seq" sequence } { "elt" object } }
{ $description "Outputs the least element of " { $snippet "seq" } "." }
{ $examples
    "Example:"
    { $example "USING: sequences prettyprint ;"
        "{ 1 2 3 4 5 } infimum ."
        "1"
    }
    "Example:"
    { $example "USING: sequences prettyprint ;"
        "{ \"c\" \"b\" \"a\" } infimum ."
        "\"a\""
    }
}
{ $errors "Throws an error if the sequence is empty." } ;

HELP: infimum-by
{ $values
    { "seq" sequence } { "quot" quotation }
    { "elt" object }
}
{ $description "Outputs the least element of " { $snippet "seq" } " according to the " { $snippet "quot" } "." }
{ $examples
    "Example:"
    { $example "USING: sequences prettyprint ;"
        "{ { 1 2 } { 1 2 3 } { 1 2 3 4 } } [ length ] infimum-by ."
        "{ 1 2 }"
    }
}
{ $errors "Throws an error if the sequence is empty." } ;

HELP: supremum
{ $values { "seq" sequence } { "elt" object } }
{ $description "Outputs the greatest element of " { $snippet "seq" } "." }
{ $examples
    "Example:"
    { $example "USING: sequences prettyprint ;"
        "{ 1 2 3 4 5 } supremum ."
        "5"
    }
    "Example:"
    { $example "USING: sequences prettyprint ;"
        "{ \"c\" \"b\" \"a\" } supremum ."
        "\"c\""
    }
}
{ $errors "Throws an error if the sequence is empty." } ;

HELP: supremum-by
{ $values
    { "seq" sequence } { "quot" quotation }
    { "elt" object }
}
{ $description "Outputs the greatest element of " { $snippet "seq" } " according to the " { $snippet "quot" } "." }
{ $examples
    "Example:"
    { $example "USING: sequences prettyprint ;"
        "{ { 1 2 } { 1 2 3 } { 1 2 3 4 } } [ length ] supremum-by ."
        "{ 1 2 3 4 }"
    }
}
{ $errors "Throws an error if the sequence is empty." } ;

{ min max infimum infimum-by supremum supremum-by } related-words

HELP: shortest
{ $values { "seqs" sequence } { "elt" object } }
