k,n:
. k = n+1 
k! = k
n! 
m,k:. 1 
m k (k',m':. k' = k-1 m' = m-1 k!m = kk'!m' )| Rank | Theorem | Name |
| 4 | k,n:. k = n+1 k! = kn! | [factorial_via_intseg_step] |
| cites the following: | ||
| 3 | m,k:. 1 m k (k',m':. k' = k-1 m' = m-1 k!m = kk'!m' ) | [factorial_tail_via_iter_step] |