Database BASIC TOPOLOGY Topology Separated spaces: T0, T1, T2 (Hausdorff) ... df-cnrm  
				
		 
		
			
		 
		Description:   Define completely normal spaces.  A space is completely normal if all
       its subspaces are normal.  (Contributed by Mario Carneiro , 26-Aug-2015) 
		
			
				
					Ref 
					Expression 
				 
				
					Assertion 
					df-cnrm   ⊢   CNrm  =   j  ∈  Top  |   ∀  x  ∈   𝒫   ⋃  j       j  ↾  𝑡 x ∈  Nrm             
				 
			
		 
		
				Detailed syntax breakdown 
				
					
						Step 
						Hyp 
						Ref 
						Expression 
					 
						
							0 
								
							 
							ccnrm  class  CNrm    
						
							1 
								
							 
							vj  setvar  j    
						
							2 
								
							 
							ctop  class  Top    
						
							3 
								
							 
							vx  setvar  x    
						
							4 
								1 
							 
							cv  setvar  j    
						
							5 
								4 
							 
							cuni  class   ⋃  j      
						
							6 
								5 
							 
							cpw  class   𝒫   ⋃  j        
						
							7 
								
							 
							crest  class  ↾  𝑡    
						
							8 
								3 
							 
							cv  setvar  x    
						
							9 
								4  8  7 
							 
							co  class  j  ↾  𝑡 x    
						
							10 
								
							 
							cnrm  class  Nrm    
						
							11 
								9  10 
							 
							wcel  wff   j  ↾  𝑡 x ∈  Nrm      
						
							12 
								11  3  6 
							 
							wral  wff   ∀  x  ∈   𝒫   ⋃  j       j  ↾  𝑡 x ∈  Nrm        
						
							13 
								12  1  2 
							 
							crab  class   j  ∈  Top  |   ∀  x  ∈   𝒫   ⋃  j       j  ↾  𝑡 x ∈  Nrm          
						
							14 
								0  13 
							 
							wceq  wff   CNrm  =   j  ∈  Top  |   ∀  x  ∈   𝒫   ⋃  j       j  ↾  𝑡 x ∈  Nrm