At: fun preserves fin111111111 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 & f1 o g1 = Id 11. f:((nn1)(n1n)). Bij(nn1; (n1n); f)
n:, f:(nST), g:((ST)n). g o f = Id & f o g = Id (ST)ST By: RWH
(LemmaC
Thm* (f:(AB). Bij(A; B; f)) (A ~ B))
11 Generated subgoal: