1 | 4. a1,a2: n. f(a1) = f(a2)  a1 = a2 5. p: m ( List) 6. sum(||p(j)|| | j < m) = n 7. j: m, x,y: ||p(j)||. x < y  (p(j))[x] > (p(j))[y] 8. j: m, x: ||p(j)||. (p(j))[x] < n & f((p(j))[x]) = j 9. j: m 10. x: ||p(j)||. (p(j))[x] < n & f((p(j))[x]) = j 11. x,y: ||p(j)||. x < y  (p(j))[x] > (p(j))[y] 12. ||p(j)|| 1 13. (p(j))[0] < n 14. f((p(j))[0]) = j 15. (p(j))[1] < n 16. f((p(j))[1]) = j 17. (p(j))[0] > (p(j))[1] (p(j))[0] n | 2 steps |
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2 | 4. a1,a2: n. f(a1) = f(a2)  a1 = a2 5. p: m ( List) 6. sum(||p(j)|| | j < m) = n 7. j: m, x,y: ||p(j)||. x < y  (p(j))[x] > (p(j))[y] 8. j: m, x: ||p(j)||. (p(j))[x] < n & f((p(j))[x]) = j 9. j: m 10. x: ||p(j)||. (p(j))[x] < n & f((p(j))[x]) = j 11. x,y: ||p(j)||. x < y  (p(j))[x] > (p(j))[y] 12. ||p(j)|| 1 13. (p(j))[0] < n 14. f((p(j))[0]) = j 15. (p(j))[1] < n 16. f((p(j))[1]) = j 17. (p(j))[0] > (p(j))[1] (p(j))[1] n | 2 steps |