At: fun preserves fin111111111111111112 1. S: Type 2. T: Type 3. n: 4. f: nS 5. g: Sn 6. g o f = Id & f o g = Id 7. n1: 8. f1: n1T 9. g1: Tn1 10. g1 o f1 = Id 11. f1 o g1 = Id 12. f2: (nn1)(n1n) 13. g2: (n1n)nn1 14. g2 o f2 = Id 15. f2 o g2 = Id
(h.f1 o g2(h) o g) o (h.f2(g1 o h o f)) = Id By: Ext Generated subgoal: