Database  
				SUPPLEMENTARY MATERIAL (USERS' MATHBOXES)  
				Mathbox for Alexander van der Vekens  
				Number theory (extension 2)  
				Goldbach's conjectures  
				df-gbe  
			 
				
		 
		 Metamath Proof Explorer 
		
			
		 
		 
		
		Description:   Define the set of (even) Goldbach numbers, which are positive even
       integers that can be expressed as the sum of two odd primes.  By this
       definition, the binary Goldbach conjecture can be expressed as
       A. n e. Even ( 4 < n -> n e. GoldbachEven )  .  (Contributed by AV , 14-Jun-2020) 
		
			
				
					 
					 
					Ref 
					Expression 
				 
				
					 
					Assertion 
					df-gbe  
					⊢    GoldbachEven   =  { 𝑧   ∈   Even   ∣  ∃ 𝑝   ∈  ℙ ∃ 𝑞   ∈  ℙ ( 𝑝   ∈   Odd   ∧  𝑞   ∈   Odd   ∧  𝑧   =  ( 𝑝   +  𝑞  ) ) }  
				 
			
		 
		 
			
				Detailed syntax breakdown 
				
					
						Step 
						Hyp 
						Ref 
						Expression 
					 
						
							0  
							
								
							 
							cgbe  
							⊢   GoldbachEven   
						 
						
							1  
							
								
							 
							vz  
							⊢  𝑧   
						 
						
							2  
							
								
							 
							ceven  
							⊢   Even   
						 
						
							3  
							
								
							 
							vp  
							⊢  𝑝   
						 
						
							4  
							
								
							 
							cprime  
							⊢  ℙ  
						 
						
							5  
							
								
							 
							vq  
							⊢  𝑞   
						 
						
							6  
							
								3 
							 
							cv  
							⊢  𝑝   
						 
						
							7  
							
								
							 
							codd  
							⊢   Odd   
						 
						
							8  
							
								6  7 
							 
							wcel  
							⊢  𝑝   ∈   Odd   
						 
						
							9  
							
								5 
							 
							cv  
							⊢  𝑞   
						 
						
							10  
							
								9  7 
							 
							wcel  
							⊢  𝑞   ∈   Odd   
						 
						
							11  
							
								1 
							 
							cv  
							⊢  𝑧   
						 
						
							12  
							
								
							 
							caddc  
							⊢   +   
						 
						
							13  
							
								6  9  12 
							 
							co  
							⊢  ( 𝑝   +  𝑞  )  
						 
						
							14  
							
								11  13 
							 
							wceq  
							⊢  𝑧   =  ( 𝑝   +  𝑞  )  
						 
						
							15  
							
								8  10  14 
							 
							w3a  
							⊢  ( 𝑝   ∈   Odd   ∧  𝑞   ∈   Odd   ∧  𝑧   =  ( 𝑝   +  𝑞  ) )  
						 
						
							16  
							
								15  5  4 
							 
							wrex  
							⊢  ∃ 𝑞   ∈  ℙ ( 𝑝   ∈   Odd   ∧  𝑞   ∈   Odd   ∧  𝑧   =  ( 𝑝   +  𝑞  ) )  
						 
						
							17  
							
								16  3  4 
							 
							wrex  
							⊢  ∃ 𝑝   ∈  ℙ ∃ 𝑞   ∈  ℙ ( 𝑝   ∈   Odd   ∧  𝑞   ∈   Odd   ∧  𝑧   =  ( 𝑝   +  𝑞  ) )  
						 
						
							18  
							
								17  1  2 
							 
							crab  
							⊢  { 𝑧   ∈   Even   ∣  ∃ 𝑝   ∈  ℙ ∃ 𝑞   ∈  ℙ ( 𝑝   ∈   Odd   ∧  𝑞   ∈   Odd   ∧  𝑧   =  ( 𝑝   +  𝑞  ) ) }  
						 
						
							19  
							
								0  18 
							 
							wceq  
							⊢   GoldbachEven   =  { 𝑧   ∈   Even   ∣  ∃ 𝑝   ∈  ℙ ∃ 𝑞   ∈  ℙ ( 𝑝   ∈   Odd   ∧  𝑞   ∈   Odd   ∧  𝑧   =  ( 𝑝   +  𝑞  ) ) }