Metamath Proof Explorer
		
		
		
		Description:  The product of two nonzero numbers is nonzero.  (Contributed by NM, 15-Feb-1995)
		
			
				
					 | 
					 | 
					Ref | 
					Expression | 
				
					
						 | 
						Hypotheses | 
						muln0.1 | 
						⊢ 𝐴  ∈  ℂ  | 
					
					
						 | 
						 | 
						muln0.2 | 
						⊢ 𝐵  ∈  ℂ  | 
					
					
						 | 
						 | 
						muln0.3 | 
						⊢ 𝐴  ≠  0  | 
					
					
						 | 
						 | 
						muln0.4 | 
						⊢ 𝐵  ≠  0  | 
					
				
					 | 
					Assertion | 
					mulne0i | 
					⊢  ( 𝐴  ·  𝐵 )  ≠  0  | 
				
			
		
		
			
				Proof
				
					
						| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							muln0.1 | 
							⊢ 𝐴  ∈  ℂ  | 
						
						
							| 2 | 
							
								
							 | 
							muln0.2 | 
							⊢ 𝐵  ∈  ℂ  | 
						
						
							| 3 | 
							
								
							 | 
							muln0.3 | 
							⊢ 𝐴  ≠  0  | 
						
						
							| 4 | 
							
								
							 | 
							muln0.4 | 
							⊢ 𝐵  ≠  0  | 
						
						
							| 5 | 
							
								
							 | 
							mulne0 | 
							⊢ ( ( ( 𝐴  ∈  ℂ  ∧  𝐴  ≠  0 )  ∧  ( 𝐵  ∈  ℂ  ∧  𝐵  ≠  0 ) )  →  ( 𝐴  ·  𝐵 )  ≠  0 )  | 
						
						
							| 6 | 
							
								1 3 2 4 5
							 | 
							mp4an | 
							⊢ ( 𝐴  ·  𝐵 )  ≠  0  |