Metamath Proof Explorer
		
		
		
		Description:  The product of two nonzero numbers is nonzero.  (Contributed by Mario
       Carneiro, 27-May-2016)
		
			
				
					|  |  | Ref | Expression | 
					
						|  | Hypotheses | msq0d.1 | ⊢ ( 𝜑  →  𝐴  ∈  ℂ ) | 
					
						|  |  | mul0ord.2 | ⊢ ( 𝜑  →  𝐵  ∈  ℂ ) | 
					
						|  |  | mulne0d.3 | ⊢ ( 𝜑  →  𝐴  ≠  0 ) | 
					
						|  |  | mulne0d.4 | ⊢ ( 𝜑  →  𝐵  ≠  0 ) | 
				
					|  | Assertion | mulne0d | ⊢  ( 𝜑  →  ( 𝐴  ·  𝐵 )  ≠  0 ) | 
			
		
		
			
				Proof
				
					
						| Step | Hyp | Ref | Expression | 
						
							| 1 |  | msq0d.1 | ⊢ ( 𝜑  →  𝐴  ∈  ℂ ) | 
						
							| 2 |  | mul0ord.2 | ⊢ ( 𝜑  →  𝐵  ∈  ℂ ) | 
						
							| 3 |  | mulne0d.3 | ⊢ ( 𝜑  →  𝐴  ≠  0 ) | 
						
							| 4 |  | mulne0d.4 | ⊢ ( 𝜑  →  𝐵  ≠  0 ) | 
						
							| 5 | 1 2 | mulne0bd | ⊢ ( 𝜑  →  ( ( 𝐴  ≠  0  ∧  𝐵  ≠  0 )  ↔  ( 𝐴  ·  𝐵 )  ≠  0 ) ) | 
						
							| 6 | 3 4 5 | mpbi2and | ⊢ ( 𝜑  →  ( 𝐴  ·  𝐵 )  ≠  0 ) |