1 |
4. f : n 
5. m: (n-1). sum(f(x) | x < n-1) = f(m)+sum(if x= m 0 else f(x) fi | x < n-1)
6. m : n
7. m = n-1
sum(f(x) | x < n) = f(m)+sum(if x= m 0 else f(x) fi | x < n)
 | 4 steps |
2 |
4. f : n 
5. m: (n-1). sum(f(x) | x < n-1) = f(m)+sum(if x= m 0 else f(x) fi | x < n-1)
6. m : n
7. m = n-1
sum(f(x) | x < n) = f(m)+sum(if x= m 0 else f(x) fi | x < n)
 | 3 steps |