At: fun preserves fin11111111 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
n:, f:(nST), g:((ST)n). g o f = Id & f o g = Id (ST)ST By: Inst
Thm*n,m:. f:((mn)(nm)). Bij(mn; (nm); f)
[n1;n] Generated subgoal: