Database  
				SUPPLEMENTARY MATERIAL (USERS' MATHBOXES)  
				Mathbox for Peter Mazsa  
				Equivalence relations on domain quotients  
				dferALTV2  
			 
				
		 
		 Metamath Proof Explorer 
		
			
		 
		 
		
		Description:   Equivalence relation with natural domain predicate, see the comment of
     df-ers  .  (Contributed by Peter Mazsa , 26-Jun-2021)   (Revised by Peter
     Mazsa , 30-Aug-2021) 
		
			
				
					 
					 
					Ref 
					Expression 
				 
				
					 
					Assertion 
					dferALTV2  
					   ⊢  R  ErALTV  A   ↔   EqvRel  R   ∧     dom  ⁡  R    /  R    =  A            
				 
			
		 
		 
			
				Proof 
				
					
						Step 
						Hyp 
						Ref 
						Expression 
					 
						
							1  
							
								
							 
							df-erALTV  
							    ⊢  R  ErALTV  A   ↔   EqvRel  R   ∧  R  DomainQs  A           
						 
						
							2  
							
								
							 
							df-dmqs  
							    ⊢  R  DomainQs  A   ↔     dom  ⁡  R    /  R    =  A         
						 
						
							3  
							
								2 
							 
							anbi2i  
							    ⊢   EqvRel  R   ∧  R  DomainQs  A      ↔   EqvRel  R   ∧     dom  ⁡  R    /  R    =  A            
						 
						
							4  
							
								1  3 
							 
							bitri  
							    ⊢  R  ErALTV  A   ↔   EqvRel  R   ∧     dom  ⁡  R    /  R    =  A