Description: Closure law for rising factorial. (Contributed by Scott Fenton, 5-Jan-2018)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | nn0risefaccl | |- ( ( A e. NN0 /\ N e. NN0 ) -> ( A RiseFac N ) e. NN0 ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | nn0sscn | |- NN0 C_ CC | |
| 2 | 1nn0 | |- 1 e. NN0 | |
| 3 | nn0mulcl | |- ( ( x e. NN0 /\ y e. NN0 ) -> ( x x. y ) e. NN0 ) | |
| 4 | nn0addcl | |- ( ( A e. NN0 /\ k e. NN0 ) -> ( A + k ) e. NN0 ) | |
| 5 | 1 2 3 4 | risefaccllem | |- ( ( A e. NN0 /\ N e. NN0 ) -> ( A RiseFac N ) e. NN0 ) |