Metamath Proof Explorer
		
		
		
		Description:  Closure of exponentiation of nonnegative integers.  (Contributed by Mario Carneiro, 28-May-2016)
		
			
				
					|  |  | Ref | Expression | 
					
						|  | Hypotheses | nn0expcld.1 | ⊢ ( 𝜑  →  𝐴  ∈  ℕ0 ) | 
					
						|  |  | nn0expcld.2 | ⊢ ( 𝜑  →  𝑁  ∈  ℕ0 ) | 
				
					|  | Assertion | nn0expcld | ⊢  ( 𝜑  →  ( 𝐴 ↑ 𝑁 )  ∈  ℕ0 ) | 
			
		
		
			
				Proof
				
					
						| Step | Hyp | Ref | Expression | 
						
							| 1 |  | nn0expcld.1 | ⊢ ( 𝜑  →  𝐴  ∈  ℕ0 ) | 
						
							| 2 |  | nn0expcld.2 | ⊢ ( 𝜑  →  𝑁  ∈  ℕ0 ) | 
						
							| 3 |  | nn0expcl | ⊢ ( ( 𝐴  ∈  ℕ0  ∧  𝑁  ∈  ℕ0 )  →  ( 𝐴 ↑ 𝑁 )  ∈  ℕ0 ) | 
						
							| 4 | 1 2 3 | syl2anc | ⊢ ( 𝜑  →  ( 𝐴 ↑ 𝑁 )  ∈  ℕ0 ) |