Y are two unipotent maps. Since f is a unipotent cover on X , t is not disjoint with f . This shows that f is unipotent. Suppose S and T are two sets of maps to Y . The pullbacks of normal monos are normal monos.
Y are two normal monos.
If A is an analytic category then any singular or analytic mono is normal. If A has pullbacks, then a mono is normal iff its pullback along any map is not proper unipotent. Conversely, assume the condition is satisfied. This shows that u is normal. Suppose C is a uni-dense class of objects.