Database CLASSICAL FIRST-ORDER LOGIC WITH EQUALITY Propositional calculus Abbreviated conjunction and disjunction of three wff's mp3an3an  
				
		 
		
			
		 
		Description:   mp3an  with antecedents in standard conjunction form and with two
       hypotheses which are implications.  (Contributed by Alan Sare , 28-Aug-2016) 
		
			
				
					Ref 
					Expression 
				 
					
						Hypotheses 
						mp3an3an.1   ⊢   φ      
					 
					
						mp3an3an.2    ⊢   ψ   →   χ        
					 
					
						mp3an3an.3    ⊢   θ   →   τ        
					 
					
						mp3an3an.4    ⊢    φ   ∧   χ   ∧   τ    →   η        
					 
				
					Assertion 
					mp3an3an    ⊢    ψ   ∧   θ    →   η        
				 
			
		 
		
				Proof 
				
					
						Step 
						Hyp 
						Ref 
						Expression 
					 
						
							1 
								
							 
							mp3an3an.1  ⊢   φ      
						
							2 
								
							 
							mp3an3an.2   ⊢   ψ   →   χ        
						
							3 
								
							 
							mp3an3an.3   ⊢   θ   →   τ        
						
							4 
								
							 
							mp3an3an.4   ⊢    φ   ∧   χ   ∧   τ    →   η        
						
							5 
								1  4 
							 
							mp3an1   ⊢    χ   ∧   τ    →   η        
						
							6 
								2  3  5 
							 
							syl2an   ⊢    ψ   ∧   θ    →   η