| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							ovex | 
							⊢ ( ( ( bra ‘ 𝐴 ) ‘ 𝐵 )  ·  ( ( bra ‘ 𝐶 ) ‘ 𝑥 ) )  ∈  V  | 
						
						
							| 2 | 
							
								
							 | 
							eqid | 
							⊢ ( 𝑥  ∈   ℋ  ↦  ( ( ( bra ‘ 𝐴 ) ‘ 𝐵 )  ·  ( ( bra ‘ 𝐶 ) ‘ 𝑥 ) ) )  =  ( 𝑥  ∈   ℋ  ↦  ( ( ( bra ‘ 𝐴 ) ‘ 𝐵 )  ·  ( ( bra ‘ 𝐶 ) ‘ 𝑥 ) ) )  | 
						
						
							| 3 | 
							
								1 2
							 | 
							fnmpti | 
							⊢ ( 𝑥  ∈   ℋ  ↦  ( ( ( bra ‘ 𝐴 ) ‘ 𝐵 )  ·  ( ( bra ‘ 𝐶 ) ‘ 𝑥 ) ) )  Fn   ℋ  | 
						
						
							| 4 | 
							
								
							 | 
							bracl | 
							⊢ ( ( 𝐴  ∈   ℋ  ∧  𝐵  ∈   ℋ )  →  ( ( bra ‘ 𝐴 ) ‘ 𝐵 )  ∈  ℂ )  | 
						
						
							| 5 | 
							
								
							 | 
							brafn | 
							⊢ ( 𝐶  ∈   ℋ  →  ( bra ‘ 𝐶 ) :  ℋ ⟶ ℂ )  | 
						
						
							| 6 | 
							
								
							 | 
							hfmmval | 
							⊢ ( ( ( ( bra ‘ 𝐴 ) ‘ 𝐵 )  ∈  ℂ  ∧  ( bra ‘ 𝐶 ) :  ℋ ⟶ ℂ )  →  ( ( ( bra ‘ 𝐴 ) ‘ 𝐵 )  ·fn  ( bra ‘ 𝐶 ) )  =  ( 𝑥  ∈   ℋ  ↦  ( ( ( bra ‘ 𝐴 ) ‘ 𝐵 )  ·  ( ( bra ‘ 𝐶 ) ‘ 𝑥 ) ) ) )  | 
						
						
							| 7 | 
							
								4 5 6
							 | 
							syl2an | 
							⊢ ( ( ( 𝐴  ∈   ℋ  ∧  𝐵  ∈   ℋ )  ∧  𝐶  ∈   ℋ )  →  ( ( ( bra ‘ 𝐴 ) ‘ 𝐵 )  ·fn  ( bra ‘ 𝐶 ) )  =  ( 𝑥  ∈   ℋ  ↦  ( ( ( bra ‘ 𝐴 ) ‘ 𝐵 )  ·  ( ( bra ‘ 𝐶 ) ‘ 𝑥 ) ) ) )  | 
						
						
							| 8 | 
							
								7
							 | 
							3impa | 
							⊢ ( ( 𝐴  ∈   ℋ  ∧  𝐵  ∈   ℋ  ∧  𝐶  ∈   ℋ )  →  ( ( ( bra ‘ 𝐴 ) ‘ 𝐵 )  ·fn  ( bra ‘ 𝐶 ) )  =  ( 𝑥  ∈   ℋ  ↦  ( ( ( bra ‘ 𝐴 ) ‘ 𝐵 )  ·  ( ( bra ‘ 𝐶 ) ‘ 𝑥 ) ) ) )  | 
						
						
							| 9 | 
							
								8
							 | 
							fneq1d | 
							⊢ ( ( 𝐴  ∈   ℋ  ∧  𝐵  ∈   ℋ  ∧  𝐶  ∈   ℋ )  →  ( ( ( ( bra ‘ 𝐴 ) ‘ 𝐵 )  ·fn  ( bra ‘ 𝐶 ) )  Fn   ℋ  ↔  ( 𝑥  ∈   ℋ  ↦  ( ( ( bra ‘ 𝐴 ) ‘ 𝐵 )  ·  ( ( bra ‘ 𝐶 ) ‘ 𝑥 ) ) )  Fn   ℋ ) )  | 
						
						
							| 10 | 
							
								3 9
							 | 
							mpbiri | 
							⊢ ( ( 𝐴  ∈   ℋ  ∧  𝐵  ∈   ℋ  ∧  𝐶  ∈   ℋ )  →  ( ( ( bra ‘ 𝐴 ) ‘ 𝐵 )  ·fn  ( bra ‘ 𝐶 ) )  Fn   ℋ )  | 
						
						
							| 11 | 
							
								
							 | 
							brafn | 
							⊢ ( 𝐴  ∈   ℋ  →  ( bra ‘ 𝐴 ) :  ℋ ⟶ ℂ )  | 
						
						
							| 12 | 
							
								
							 | 
							kbop | 
							⊢ ( ( 𝐵  ∈   ℋ  ∧  𝐶  ∈   ℋ )  →  ( 𝐵  ketbra  𝐶 ) :  ℋ ⟶  ℋ )  | 
						
						
							| 13 | 
							
								
							 | 
							fco | 
							⊢ ( ( ( bra ‘ 𝐴 ) :  ℋ ⟶ ℂ  ∧  ( 𝐵  ketbra  𝐶 ) :  ℋ ⟶  ℋ )  →  ( ( bra ‘ 𝐴 )  ∘  ( 𝐵  ketbra  𝐶 ) ) :  ℋ ⟶ ℂ )  | 
						
						
							| 14 | 
							
								11 12 13
							 | 
							syl2an | 
							⊢ ( ( 𝐴  ∈   ℋ  ∧  ( 𝐵  ∈   ℋ  ∧  𝐶  ∈   ℋ ) )  →  ( ( bra ‘ 𝐴 )  ∘  ( 𝐵  ketbra  𝐶 ) ) :  ℋ ⟶ ℂ )  | 
						
						
							| 15 | 
							
								14
							 | 
							3impb | 
							⊢ ( ( 𝐴  ∈   ℋ  ∧  𝐵  ∈   ℋ  ∧  𝐶  ∈   ℋ )  →  ( ( bra ‘ 𝐴 )  ∘  ( 𝐵  ketbra  𝐶 ) ) :  ℋ ⟶ ℂ )  | 
						
						
							| 16 | 
							
								15
							 | 
							ffnd | 
							⊢ ( ( 𝐴  ∈   ℋ  ∧  𝐵  ∈   ℋ  ∧  𝐶  ∈   ℋ )  →  ( ( bra ‘ 𝐴 )  ∘  ( 𝐵  ketbra  𝐶 ) )  Fn   ℋ )  | 
						
						
							| 17 | 
							
								
							 | 
							simpl1 | 
							⊢ ( ( ( 𝐴  ∈   ℋ  ∧  𝐵  ∈   ℋ  ∧  𝐶  ∈   ℋ )  ∧  𝑥  ∈   ℋ )  →  𝐴  ∈   ℋ )  | 
						
						
							| 18 | 
							
								
							 | 
							simpl2 | 
							⊢ ( ( ( 𝐴  ∈   ℋ  ∧  𝐵  ∈   ℋ  ∧  𝐶  ∈   ℋ )  ∧  𝑥  ∈   ℋ )  →  𝐵  ∈   ℋ )  | 
						
						
							| 19 | 
							
								
							 | 
							braval | 
							⊢ ( ( 𝐴  ∈   ℋ  ∧  𝐵  ∈   ℋ )  →  ( ( bra ‘ 𝐴 ) ‘ 𝐵 )  =  ( 𝐵  ·ih  𝐴 ) )  | 
						
						
							| 20 | 
							
								17 18 19
							 | 
							syl2anc | 
							⊢ ( ( ( 𝐴  ∈   ℋ  ∧  𝐵  ∈   ℋ  ∧  𝐶  ∈   ℋ )  ∧  𝑥  ∈   ℋ )  →  ( ( bra ‘ 𝐴 ) ‘ 𝐵 )  =  ( 𝐵  ·ih  𝐴 ) )  | 
						
						
							| 21 | 
							
								
							 | 
							simpl3 | 
							⊢ ( ( ( 𝐴  ∈   ℋ  ∧  𝐵  ∈   ℋ  ∧  𝐶  ∈   ℋ )  ∧  𝑥  ∈   ℋ )  →  𝐶  ∈   ℋ )  | 
						
						
							| 22 | 
							
								
							 | 
							simpr | 
							⊢ ( ( ( 𝐴  ∈   ℋ  ∧  𝐵  ∈   ℋ  ∧  𝐶  ∈   ℋ )  ∧  𝑥  ∈   ℋ )  →  𝑥  ∈   ℋ )  | 
						
						
							| 23 | 
							
								
							 | 
							braval | 
							⊢ ( ( 𝐶  ∈   ℋ  ∧  𝑥  ∈   ℋ )  →  ( ( bra ‘ 𝐶 ) ‘ 𝑥 )  =  ( 𝑥  ·ih  𝐶 ) )  | 
						
						
							| 24 | 
							
								21 22 23
							 | 
							syl2anc | 
							⊢ ( ( ( 𝐴  ∈   ℋ  ∧  𝐵  ∈   ℋ  ∧  𝐶  ∈   ℋ )  ∧  𝑥  ∈   ℋ )  →  ( ( bra ‘ 𝐶 ) ‘ 𝑥 )  =  ( 𝑥  ·ih  𝐶 ) )  | 
						
						
							| 25 | 
							
								20 24
							 | 
							oveq12d | 
							⊢ ( ( ( 𝐴  ∈   ℋ  ∧  𝐵  ∈   ℋ  ∧  𝐶  ∈   ℋ )  ∧  𝑥  ∈   ℋ )  →  ( ( ( bra ‘ 𝐴 ) ‘ 𝐵 )  ·  ( ( bra ‘ 𝐶 ) ‘ 𝑥 ) )  =  ( ( 𝐵  ·ih  𝐴 )  ·  ( 𝑥  ·ih  𝐶 ) ) )  | 
						
						
							| 26 | 
							
								
							 | 
							hicl | 
							⊢ ( ( 𝐵  ∈   ℋ  ∧  𝐴  ∈   ℋ )  →  ( 𝐵  ·ih  𝐴 )  ∈  ℂ )  | 
						
						
							| 27 | 
							
								18 17 26
							 | 
							syl2anc | 
							⊢ ( ( ( 𝐴  ∈   ℋ  ∧  𝐵  ∈   ℋ  ∧  𝐶  ∈   ℋ )  ∧  𝑥  ∈   ℋ )  →  ( 𝐵  ·ih  𝐴 )  ∈  ℂ )  | 
						
						
							| 28 | 
							
								20 27
							 | 
							eqeltrd | 
							⊢ ( ( ( 𝐴  ∈   ℋ  ∧  𝐵  ∈   ℋ  ∧  𝐶  ∈   ℋ )  ∧  𝑥  ∈   ℋ )  →  ( ( bra ‘ 𝐴 ) ‘ 𝐵 )  ∈  ℂ )  | 
						
						
							| 29 | 
							
								21 5
							 | 
							syl | 
							⊢ ( ( ( 𝐴  ∈   ℋ  ∧  𝐵  ∈   ℋ  ∧  𝐶  ∈   ℋ )  ∧  𝑥  ∈   ℋ )  →  ( bra ‘ 𝐶 ) :  ℋ ⟶ ℂ )  | 
						
						
							| 30 | 
							
								
							 | 
							hfmval | 
							⊢ ( ( ( ( bra ‘ 𝐴 ) ‘ 𝐵 )  ∈  ℂ  ∧  ( bra ‘ 𝐶 ) :  ℋ ⟶ ℂ  ∧  𝑥  ∈   ℋ )  →  ( ( ( ( bra ‘ 𝐴 ) ‘ 𝐵 )  ·fn  ( bra ‘ 𝐶 ) ) ‘ 𝑥 )  =  ( ( ( bra ‘ 𝐴 ) ‘ 𝐵 )  ·  ( ( bra ‘ 𝐶 ) ‘ 𝑥 ) ) )  | 
						
						
							| 31 | 
							
								28 29 22 30
							 | 
							syl3anc | 
							⊢ ( ( ( 𝐴  ∈   ℋ  ∧  𝐵  ∈   ℋ  ∧  𝐶  ∈   ℋ )  ∧  𝑥  ∈   ℋ )  →  ( ( ( ( bra ‘ 𝐴 ) ‘ 𝐵 )  ·fn  ( bra ‘ 𝐶 ) ) ‘ 𝑥 )  =  ( ( ( bra ‘ 𝐴 ) ‘ 𝐵 )  ·  ( ( bra ‘ 𝐶 ) ‘ 𝑥 ) ) )  | 
						
						
							| 32 | 
							
								
							 | 
							hicl | 
							⊢ ( ( 𝑥  ∈   ℋ  ∧  𝐶  ∈   ℋ )  →  ( 𝑥  ·ih  𝐶 )  ∈  ℂ )  | 
						
						
							| 33 | 
							
								22 21 32
							 | 
							syl2anc | 
							⊢ ( ( ( 𝐴  ∈   ℋ  ∧  𝐵  ∈   ℋ  ∧  𝐶  ∈   ℋ )  ∧  𝑥  ∈   ℋ )  →  ( 𝑥  ·ih  𝐶 )  ∈  ℂ )  | 
						
						
							| 34 | 
							
								
							 | 
							ax-his3 | 
							⊢ ( ( ( 𝑥  ·ih  𝐶 )  ∈  ℂ  ∧  𝐵  ∈   ℋ  ∧  𝐴  ∈   ℋ )  →  ( ( ( 𝑥  ·ih  𝐶 )  ·ℎ  𝐵 )  ·ih  𝐴 )  =  ( ( 𝑥  ·ih  𝐶 )  ·  ( 𝐵  ·ih  𝐴 ) ) )  | 
						
						
							| 35 | 
							
								33 18 17 34
							 | 
							syl3anc | 
							⊢ ( ( ( 𝐴  ∈   ℋ  ∧  𝐵  ∈   ℋ  ∧  𝐶  ∈   ℋ )  ∧  𝑥  ∈   ℋ )  →  ( ( ( 𝑥  ·ih  𝐶 )  ·ℎ  𝐵 )  ·ih  𝐴 )  =  ( ( 𝑥  ·ih  𝐶 )  ·  ( 𝐵  ·ih  𝐴 ) ) )  | 
						
						
							| 36 | 
							
								12
							 | 
							3adant1 | 
							⊢ ( ( 𝐴  ∈   ℋ  ∧  𝐵  ∈   ℋ  ∧  𝐶  ∈   ℋ )  →  ( 𝐵  ketbra  𝐶 ) :  ℋ ⟶  ℋ )  | 
						
						
							| 37 | 
							
								
							 | 
							fvco3 | 
							⊢ ( ( ( 𝐵  ketbra  𝐶 ) :  ℋ ⟶  ℋ  ∧  𝑥  ∈   ℋ )  →  ( ( ( bra ‘ 𝐴 )  ∘  ( 𝐵  ketbra  𝐶 ) ) ‘ 𝑥 )  =  ( ( bra ‘ 𝐴 ) ‘ ( ( 𝐵  ketbra  𝐶 ) ‘ 𝑥 ) ) )  | 
						
						
							| 38 | 
							
								36 37
							 | 
							sylan | 
							⊢ ( ( ( 𝐴  ∈   ℋ  ∧  𝐵  ∈   ℋ  ∧  𝐶  ∈   ℋ )  ∧  𝑥  ∈   ℋ )  →  ( ( ( bra ‘ 𝐴 )  ∘  ( 𝐵  ketbra  𝐶 ) ) ‘ 𝑥 )  =  ( ( bra ‘ 𝐴 ) ‘ ( ( 𝐵  ketbra  𝐶 ) ‘ 𝑥 ) ) )  | 
						
						
							| 39 | 
							
								
							 | 
							kbval | 
							⊢ ( ( 𝐵  ∈   ℋ  ∧  𝐶  ∈   ℋ  ∧  𝑥  ∈   ℋ )  →  ( ( 𝐵  ketbra  𝐶 ) ‘ 𝑥 )  =  ( ( 𝑥  ·ih  𝐶 )  ·ℎ  𝐵 ) )  | 
						
						
							| 40 | 
							
								18 21 22 39
							 | 
							syl3anc | 
							⊢ ( ( ( 𝐴  ∈   ℋ  ∧  𝐵  ∈   ℋ  ∧  𝐶  ∈   ℋ )  ∧  𝑥  ∈   ℋ )  →  ( ( 𝐵  ketbra  𝐶 ) ‘ 𝑥 )  =  ( ( 𝑥  ·ih  𝐶 )  ·ℎ  𝐵 ) )  | 
						
						
							| 41 | 
							
								40
							 | 
							fveq2d | 
							⊢ ( ( ( 𝐴  ∈   ℋ  ∧  𝐵  ∈   ℋ  ∧  𝐶  ∈   ℋ )  ∧  𝑥  ∈   ℋ )  →  ( ( bra ‘ 𝐴 ) ‘ ( ( 𝐵  ketbra  𝐶 ) ‘ 𝑥 ) )  =  ( ( bra ‘ 𝐴 ) ‘ ( ( 𝑥  ·ih  𝐶 )  ·ℎ  𝐵 ) ) )  | 
						
						
							| 42 | 
							
								
							 | 
							hvmulcl | 
							⊢ ( ( ( 𝑥  ·ih  𝐶 )  ∈  ℂ  ∧  𝐵  ∈   ℋ )  →  ( ( 𝑥  ·ih  𝐶 )  ·ℎ  𝐵 )  ∈   ℋ )  | 
						
						
							| 43 | 
							
								33 18 42
							 | 
							syl2anc | 
							⊢ ( ( ( 𝐴  ∈   ℋ  ∧  𝐵  ∈   ℋ  ∧  𝐶  ∈   ℋ )  ∧  𝑥  ∈   ℋ )  →  ( ( 𝑥  ·ih  𝐶 )  ·ℎ  𝐵 )  ∈   ℋ )  | 
						
						
							| 44 | 
							
								
							 | 
							braval | 
							⊢ ( ( 𝐴  ∈   ℋ  ∧  ( ( 𝑥  ·ih  𝐶 )  ·ℎ  𝐵 )  ∈   ℋ )  →  ( ( bra ‘ 𝐴 ) ‘ ( ( 𝑥  ·ih  𝐶 )  ·ℎ  𝐵 ) )  =  ( ( ( 𝑥  ·ih  𝐶 )  ·ℎ  𝐵 )  ·ih  𝐴 ) )  | 
						
						
							| 45 | 
							
								17 43 44
							 | 
							syl2anc | 
							⊢ ( ( ( 𝐴  ∈   ℋ  ∧  𝐵  ∈   ℋ  ∧  𝐶  ∈   ℋ )  ∧  𝑥  ∈   ℋ )  →  ( ( bra ‘ 𝐴 ) ‘ ( ( 𝑥  ·ih  𝐶 )  ·ℎ  𝐵 ) )  =  ( ( ( 𝑥  ·ih  𝐶 )  ·ℎ  𝐵 )  ·ih  𝐴 ) )  | 
						
						
							| 46 | 
							
								38 41 45
							 | 
							3eqtrd | 
							⊢ ( ( ( 𝐴  ∈   ℋ  ∧  𝐵  ∈   ℋ  ∧  𝐶  ∈   ℋ )  ∧  𝑥  ∈   ℋ )  →  ( ( ( bra ‘ 𝐴 )  ∘  ( 𝐵  ketbra  𝐶 ) ) ‘ 𝑥 )  =  ( ( ( 𝑥  ·ih  𝐶 )  ·ℎ  𝐵 )  ·ih  𝐴 ) )  | 
						
						
							| 47 | 
							
								27 33
							 | 
							mulcomd | 
							⊢ ( ( ( 𝐴  ∈   ℋ  ∧  𝐵  ∈   ℋ  ∧  𝐶  ∈   ℋ )  ∧  𝑥  ∈   ℋ )  →  ( ( 𝐵  ·ih  𝐴 )  ·  ( 𝑥  ·ih  𝐶 ) )  =  ( ( 𝑥  ·ih  𝐶 )  ·  ( 𝐵  ·ih  𝐴 ) ) )  | 
						
						
							| 48 | 
							
								35 46 47
							 | 
							3eqtr4d | 
							⊢ ( ( ( 𝐴  ∈   ℋ  ∧  𝐵  ∈   ℋ  ∧  𝐶  ∈   ℋ )  ∧  𝑥  ∈   ℋ )  →  ( ( ( bra ‘ 𝐴 )  ∘  ( 𝐵  ketbra  𝐶 ) ) ‘ 𝑥 )  =  ( ( 𝐵  ·ih  𝐴 )  ·  ( 𝑥  ·ih  𝐶 ) ) )  | 
						
						
							| 49 | 
							
								25 31 48
							 | 
							3eqtr4d | 
							⊢ ( ( ( 𝐴  ∈   ℋ  ∧  𝐵  ∈   ℋ  ∧  𝐶  ∈   ℋ )  ∧  𝑥  ∈   ℋ )  →  ( ( ( ( bra ‘ 𝐴 ) ‘ 𝐵 )  ·fn  ( bra ‘ 𝐶 ) ) ‘ 𝑥 )  =  ( ( ( bra ‘ 𝐴 )  ∘  ( 𝐵  ketbra  𝐶 ) ) ‘ 𝑥 ) )  | 
						
						
							| 50 | 
							
								10 16 49
							 | 
							eqfnfvd | 
							⊢ ( ( 𝐴  ∈   ℋ  ∧  𝐵  ∈   ℋ  ∧  𝐶  ∈   ℋ )  →  ( ( ( bra ‘ 𝐴 ) ‘ 𝐵 )  ·fn  ( bra ‘ 𝐶 ) )  =  ( ( bra ‘ 𝐴 )  ∘  ( 𝐵  ketbra  𝐶 ) ) )  |