For a proposition ''f'' : ''X''<sub>1</sub> × … × ''X''<sub>''k''</sub> → '''B''', the (first order) enlargement of f is the proposition ''Ef'' : ''EU'' → '''B''' that is defined by: | For a proposition ''f'' : ''X''<sub>1</sub> × … × ''X''<sub>''k''</sub> → '''B''', the (first order) enlargement of f is the proposition ''Ef'' : ''EU'' → '''B''' that is defined by: |