Metamath Proof Explorer
		
		
		
		Description:  Infer implication from a logical equivalence.  Similar to biimpar .
       (Contributed by NM, 2-Jan-2009)
		
			
				
					 | 
					 | 
					Ref | 
					Expression | 
				
					
						 | 
						Hypothesis | 
						biimp3a.1 | 
						⊢ ( ( 𝜑  ∧  𝜓 )  →  ( 𝜒  ↔  𝜃 ) )  | 
					
				
					 | 
					Assertion | 
					biimp3ar | 
					⊢  ( ( 𝜑  ∧  𝜓  ∧  𝜃 )  →  𝜒 )  | 
				
			
		
		
			
				Proof
				
					
						| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							biimp3a.1 | 
							⊢ ( ( 𝜑  ∧  𝜓 )  →  ( 𝜒  ↔  𝜃 ) )  | 
						
						
							| 2 | 
							
								1
							 | 
							exbiri | 
							⊢ ( 𝜑  →  ( 𝜓  →  ( 𝜃  →  𝜒 ) ) )  | 
						
						
							| 3 | 
							
								2
							 | 
							3imp | 
							⊢ ( ( 𝜑  ∧  𝜓  ∧  𝜃 )  →  𝜒 )  |