| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							caovcang.1 | 
							⊢ ( ( 𝜑  ∧  ( 𝑥  ∈  𝑇  ∧  𝑦  ∈  𝑆  ∧  𝑧  ∈  𝑆 ) )  →  ( ( 𝑥 𝐹 𝑦 )  =  ( 𝑥 𝐹 𝑧 )  ↔  𝑦  =  𝑧 ) )  | 
						
						
							| 2 | 
							
								1
							 | 
							ralrimivvva | 
							⊢ ( 𝜑  →  ∀ 𝑥  ∈  𝑇 ∀ 𝑦  ∈  𝑆 ∀ 𝑧  ∈  𝑆 ( ( 𝑥 𝐹 𝑦 )  =  ( 𝑥 𝐹 𝑧 )  ↔  𝑦  =  𝑧 ) )  | 
						
						
							| 3 | 
							
								
							 | 
							oveq1 | 
							⊢ ( 𝑥  =  𝐴  →  ( 𝑥 𝐹 𝑦 )  =  ( 𝐴 𝐹 𝑦 ) )  | 
						
						
							| 4 | 
							
								
							 | 
							oveq1 | 
							⊢ ( 𝑥  =  𝐴  →  ( 𝑥 𝐹 𝑧 )  =  ( 𝐴 𝐹 𝑧 ) )  | 
						
						
							| 5 | 
							
								3 4
							 | 
							eqeq12d | 
							⊢ ( 𝑥  =  𝐴  →  ( ( 𝑥 𝐹 𝑦 )  =  ( 𝑥 𝐹 𝑧 )  ↔  ( 𝐴 𝐹 𝑦 )  =  ( 𝐴 𝐹 𝑧 ) ) )  | 
						
						
							| 6 | 
							
								5
							 | 
							bibi1d | 
							⊢ ( 𝑥  =  𝐴  →  ( ( ( 𝑥 𝐹 𝑦 )  =  ( 𝑥 𝐹 𝑧 )  ↔  𝑦  =  𝑧 )  ↔  ( ( 𝐴 𝐹 𝑦 )  =  ( 𝐴 𝐹 𝑧 )  ↔  𝑦  =  𝑧 ) ) )  | 
						
						
							| 7 | 
							
								
							 | 
							oveq2 | 
							⊢ ( 𝑦  =  𝐵  →  ( 𝐴 𝐹 𝑦 )  =  ( 𝐴 𝐹 𝐵 ) )  | 
						
						
							| 8 | 
							
								7
							 | 
							eqeq1d | 
							⊢ ( 𝑦  =  𝐵  →  ( ( 𝐴 𝐹 𝑦 )  =  ( 𝐴 𝐹 𝑧 )  ↔  ( 𝐴 𝐹 𝐵 )  =  ( 𝐴 𝐹 𝑧 ) ) )  | 
						
						
							| 9 | 
							
								
							 | 
							eqeq1 | 
							⊢ ( 𝑦  =  𝐵  →  ( 𝑦  =  𝑧  ↔  𝐵  =  𝑧 ) )  | 
						
						
							| 10 | 
							
								8 9
							 | 
							bibi12d | 
							⊢ ( 𝑦  =  𝐵  →  ( ( ( 𝐴 𝐹 𝑦 )  =  ( 𝐴 𝐹 𝑧 )  ↔  𝑦  =  𝑧 )  ↔  ( ( 𝐴 𝐹 𝐵 )  =  ( 𝐴 𝐹 𝑧 )  ↔  𝐵  =  𝑧 ) ) )  | 
						
						
							| 11 | 
							
								
							 | 
							oveq2 | 
							⊢ ( 𝑧  =  𝐶  →  ( 𝐴 𝐹 𝑧 )  =  ( 𝐴 𝐹 𝐶 ) )  | 
						
						
							| 12 | 
							
								11
							 | 
							eqeq2d | 
							⊢ ( 𝑧  =  𝐶  →  ( ( 𝐴 𝐹 𝐵 )  =  ( 𝐴 𝐹 𝑧 )  ↔  ( 𝐴 𝐹 𝐵 )  =  ( 𝐴 𝐹 𝐶 ) ) )  | 
						
						
							| 13 | 
							
								
							 | 
							eqeq2 | 
							⊢ ( 𝑧  =  𝐶  →  ( 𝐵  =  𝑧  ↔  𝐵  =  𝐶 ) )  | 
						
						
							| 14 | 
							
								12 13
							 | 
							bibi12d | 
							⊢ ( 𝑧  =  𝐶  →  ( ( ( 𝐴 𝐹 𝐵 )  =  ( 𝐴 𝐹 𝑧 )  ↔  𝐵  =  𝑧 )  ↔  ( ( 𝐴 𝐹 𝐵 )  =  ( 𝐴 𝐹 𝐶 )  ↔  𝐵  =  𝐶 ) ) )  | 
						
						
							| 15 | 
							
								6 10 14
							 | 
							rspc3v | 
							⊢ ( ( 𝐴  ∈  𝑇  ∧  𝐵  ∈  𝑆  ∧  𝐶  ∈  𝑆 )  →  ( ∀ 𝑥  ∈  𝑇 ∀ 𝑦  ∈  𝑆 ∀ 𝑧  ∈  𝑆 ( ( 𝑥 𝐹 𝑦 )  =  ( 𝑥 𝐹 𝑧 )  ↔  𝑦  =  𝑧 )  →  ( ( 𝐴 𝐹 𝐵 )  =  ( 𝐴 𝐹 𝐶 )  ↔  𝐵  =  𝐶 ) ) )  | 
						
						
							| 16 | 
							
								2 15
							 | 
							mpan9 | 
							⊢ ( ( 𝜑  ∧  ( 𝐴  ∈  𝑇  ∧  𝐵  ∈  𝑆  ∧  𝐶  ∈  𝑆 ) )  →  ( ( 𝐴 𝐹 𝐵 )  =  ( 𝐴 𝐹 𝐶 )  ↔  𝐵  =  𝐶 ) )  |