let H be Element of QC-WFF ; :: 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 Th67;
hence the_scope_of H is_proper_subformula_of H by Th73; :: thesis: verum