At: quotient of nsubn2121121121 1. n: {1+1...} 2. E:((n-1)(n-1)Prop).
(EquivRel x,y:(n-1). x E y) & (x,y:(n-1). Dec(x E y))
(m:(n-1+1). m ~ (i,j:(n-1)//(i E j))) 3. E: nnProp 4. EquivRel x,y:n. x E y 5. x,y:n. Dec(x E y) 6. EquivRel x,y:(n-1). x E y 7. m: (n-1+1) 8. f: m(i,j:(n-1)//(i E j)) 9. g: (i,j:(n-1)//(i E j))m 10. InvFuns(m; i,j:(n-1)//(i E j); f; g) 11. x:m. f(x) i,j:n//(i E j) 12. a:n. a E a 13. a,b:n. (a E b) (b E a) 14. a,b,c:n. (a E b) (b E c) (a E c) 15. x,y:i,j:n//(i E j). Dec(x = y) 16. f:((i,j:n//(i E j))(i,j:n//(i E j))). x,y:i,j:n//(i E j). (x f y) x = y
m:(n+1), f:(m(i,j:n//(i E j))), g:((i,j:n//(i E j))m). InvFuns(m; i,j:n//(i E j); f; g) By: New [`Eb'] (Analyze 16) Generated subgoal:
16. Eb: (i,j:n//(i E j))(i,j:n//(i E j)) 17. x,y:i,j:n//(i E j). (x Eb y) x = y m:(n+1), f:(m(i,j:n//(i E j))), g:((i,j:n//(i E j))m). InvFuns(m; i,j:n//(i E j); f; g)