def ShowEps(s, visible_eps):
    """Show Epsilons as '@' in printouts if visible_eps
       is set. Else suppress Epsilons (edges will carry no
       labels then.)
    """
    if (s==""):
        if visible_eps:
            return '@'
        else:
            return "''"  # Was @ once upon a time!
    else:
        return s