Database SUPPLEMENTARY MATERIAL (USERS' MATHBOXES) Mathbox for Alexander van der Vekens Even and odd numbers Alternate definitions using the "modulo" operation zefldiv2ALTV  
				
		 
		
			
		 
		Description:   The floor of an even number divided by 2 is equal to the even number
     divided by 2.  (Contributed by AV , 7-Jun-2020)   (Revised by AV , 18-Jun-2020) 
		
			
				
					Ref 
					Expression 
				 
				
					Assertion 
					zefldiv2ALTV ⊢   ( 𝑁   ∈   Even   →  ( ⌊ ‘ ( 𝑁   /  2 ) )  =  ( 𝑁   /  2 ) )  
			
		 
		
				Proof 
				
					
						Step 
						Hyp 
						Ref 
						Expression 
					 
						
							1 
								
							 
							evendiv2z ⊢  ( 𝑁   ∈   Even   →  ( 𝑁   /  2 )  ∈  ℤ )  
						
							2 
								
							 
							flid ⊢  ( ( 𝑁   /  2 )  ∈  ℤ  →  ( ⌊ ‘ ( 𝑁   /  2 ) )  =  ( 𝑁   /  2 ) )  
						
							3 
								1  2 
							 
							syl ⊢  ( 𝑁   ∈   Even   →  ( ⌊ ‘ ( 𝑁   /  2 ) )  =  ( 𝑁   /  2 ) )