Exponentiable

The result holds even if S is not exponentiable. An example is given of a category #92;mathcal#123;C#125; that satisfies the axioms, but for which there is no elementary topos #92;mathcal#123;E#125; such that #92;mathcal#123;C#125; is the category of locales over #92;mathcal#123;E#125;. It is shown, in outline, how the results can be extended from groups to groupoids..