Metamath Proof Explorer
		
		
		
		Description:  Add a zero in the units place.  (Contributed by Mario Carneiro, 18-Feb-2014)
		
			
				
					|  |  | Ref | Expression | 
					
						|  | Hypotheses | numnncl.1 | ⊢ 𝑇  ∈  ℕ0 | 
					
						|  |  | numnncl.2 | ⊢ 𝐴  ∈  ℕ0 | 
				
					|  | Assertion | num0u | ⊢  ( 𝑇  ·  𝐴 )  =  ( ( 𝑇  ·  𝐴 )  +  0 ) | 
			
		
		
			
				Proof
				
					
						| Step | Hyp | Ref | Expression | 
						
							| 1 |  | numnncl.1 | ⊢ 𝑇  ∈  ℕ0 | 
						
							| 2 |  | numnncl.2 | ⊢ 𝐴  ∈  ℕ0 | 
						
							| 3 | 1 2 | nn0mulcli | ⊢ ( 𝑇  ·  𝐴 )  ∈  ℕ0 | 
						
							| 4 | 3 | nn0cni | ⊢ ( 𝑇  ·  𝐴 )  ∈  ℂ | 
						
							| 5 | 4 | addridi | ⊢ ( ( 𝑇  ·  𝐴 )  +  0 )  =  ( 𝑇  ·  𝐴 ) | 
						
							| 6 | 5 | eqcomi | ⊢ ( 𝑇  ·  𝐴 )  =  ( ( 𝑇  ·  𝐴 )  +  0 ) |