let H be ZF-formula; :: thesis: ( H is universal implies the_scope_of H is_proper_subformula_of H )
assume H is universal ; :: thesis: the_scope_of H is_proper_subformula_of H
then the_scope_of H is_immediate_constituent_of H by Th58;
hence the_scope_of H is_proper_subformula_of H by Th61; :: thesis: verum