SYNOPSIS
        object next_inventory()
        object next_inventory(object ob)

DESCRIPTION
        Get next object in the same inventory as ob. If ob is not
        given, the current object will be used.

        This efun is mostly used together with the efun
        first_inventory().

SEE ALSO
        first_inventory(E), all_inventory(E), environment(E),
        deep_inventory(E)