^++=t/wo

c/ount elements on the stack but more complicated / end [... elem] start -- end [... elem] count
{
    + / increment counter
    %t / get last elem
    E? / if it's end then stop counting
        %t / reverse back
        #
    ;

    &e=e / pop elem saving
    @c   / end [...] start+1
    $e%t / reverse back
}

C/ount elements on the stack / [elem ...] -- [elem ...] elem-count
{
    $E / push end on the stack
    %_ / reverse the stack
    ^- @c / count elements
    &c=c / save count
    %_ / reverse back
    =_ / get rid of end
    $c / push count back
}

^-=E / end of count
^^^^^
@C