Database SUPPLEMENTARY MATERIAL (USERS' MATHBOXES) Mathbox for Jarvin Udandy aifftbifffaibif  
				
		 
		
			
		 
		Description:   Given a is equivalent to T., Given b is equivalent to F., there exists a
       proof for that a implies b is false.  (Contributed by Jarvin Udandy , 7-Sep-2020) 
		
			
				
					Ref 
					Expression 
				 
					
						Hypotheses 
						aifftbifffaibif.1 ⊢  ( 𝜑   ↔  ⊤ )  
					
						aifftbifffaibif.2 ⊢  ( 𝜓   ↔  ⊥ )  
				
					Assertion 
					aifftbifffaibif ⊢   ( ( 𝜑   →  𝜓  )  ↔  ⊥ )  
			
		 
		
				Proof 
				
					
						Step 
						Hyp 
						Ref 
						Expression 
					 
						
							1 
								
							 
							aifftbifffaibif.1 ⊢  ( 𝜑   ↔  ⊤ )  
						
							2 
								
							 
							aifftbifffaibif.2 ⊢  ( 𝜓   ↔  ⊥ )  
						
							3 
								1 
							 
							aistia ⊢  𝜑   
						
							4 
								2 
							 
							aisfina ⊢  ¬  𝜓   
						
							5 
								3  4 
							 
							pm3.2i ⊢  ( 𝜑   ∧  ¬  𝜓  )  
						
							6 
								
							 
							annim ⊢  ( ( 𝜑   ∧  ¬  𝜓  )  ↔  ¬  ( 𝜑   →  𝜓  ) )  
						
							7 
								6 
							 
							biimpi ⊢  ( ( 𝜑   ∧  ¬  𝜓  )  →  ¬  ( 𝜑   →  𝜓  ) )  
						
							8 
								5  7 
							 
							ax-mp ⊢  ¬  ( 𝜑   →  𝜓  )  
						
							9 
								8 
							 
							bifal ⊢  ( ( 𝜑   →  𝜓  )  ↔  ⊥ )