Metamath Proof Explorer
		
		
		
		Description:  The value of the rising factorial at a successor.  (Contributed by Scott
       Fenton, 19-Mar-2018)
		
			
				
					|  |  | Ref | Expression | 
					
						|  | Hypotheses | rffacp1d.1 | ⊢ ( 𝜑  →  𝐴  ∈  ℂ ) | 
					
						|  |  | rffacp1d.2 | ⊢ ( 𝜑  →  𝑁  ∈  ℕ0 ) | 
				
					|  | Assertion | risefacp1d | ⊢  ( 𝜑  →  ( 𝐴  RiseFac  ( 𝑁  +  1 ) )  =  ( ( 𝐴  RiseFac  𝑁 )  ·  ( 𝐴  +  𝑁 ) ) ) | 
			
		
		
			
				Proof
				
					
						| Step | Hyp | Ref | Expression | 
						
							| 1 |  | rffacp1d.1 | ⊢ ( 𝜑  →  𝐴  ∈  ℂ ) | 
						
							| 2 |  | rffacp1d.2 | ⊢ ( 𝜑  →  𝑁  ∈  ℕ0 ) | 
						
							| 3 |  | risefacp1 | ⊢ ( ( 𝐴  ∈  ℂ  ∧  𝑁  ∈  ℕ0 )  →  ( 𝐴  RiseFac  ( 𝑁  +  1 ) )  =  ( ( 𝐴  RiseFac  𝑁 )  ·  ( 𝐴  +  𝑁 ) ) ) | 
						
							| 4 | 1 2 3 | syl2anc | ⊢ ( 𝜑  →  ( 𝐴  RiseFac  ( 𝑁  +  1 ) )  =  ( ( 𝐴  RiseFac  𝑁 )  ·  ( 𝐴  +  𝑁 ) ) ) |