Solution

ID: past-exam-of-the-mathematics-course-of-the-university-of-cambridge/2004/iii/paper-23/5/ii/solution

Take . The category of elements has finite limits. Reversing its limiting cones gives cocones over every finite diagram in ; a terminal object before reversal ensures nonemptiness. Its opposite category is therefore a filtered category, proving (iii).

New to topics? Read the docs here!