HELP SUBSCRV                       updated Mark Rubinstein  December 1985

    subscrv(integer, vector) -> item;
    item -> subscrv(integer, vector);

This procedure is used to access and updater vectors; so if the value of
the variable S is a vector then

    s(4) =>

is equivalent to

    subscrv(4, s) =>

For example:

    {a b c d} -> s;
    s(4) =>
    ** d

    [ list] -> s(3);
    s =>
    ** {a b [list] d}

See HELP * INITV, * VECTORCLASS.