| Step | Hyp | Ref | Expression | 
						
							| 1 |  | oveq1 | ⊢ ( ( normℎ ‘ 𝐴 )  =  1  →  ( ( normℎ ‘ 𝐴 ) ↑ 2 )  =  ( 1 ↑ 2 ) ) | 
						
							| 2 |  | sq1 | ⊢ ( 1 ↑ 2 )  =  1 | 
						
							| 3 | 1 2 | eqtrdi | ⊢ ( ( normℎ ‘ 𝐴 )  =  1  →  ( ( normℎ ‘ 𝐴 ) ↑ 2 )  =  1 ) | 
						
							| 4 | 3 | oveq2d | ⊢ ( ( normℎ ‘ 𝐴 )  =  1  →  ( ( 𝑥  ·ih  𝐴 )  /  ( ( normℎ ‘ 𝐴 ) ↑ 2 ) )  =  ( ( 𝑥  ·ih  𝐴 )  /  1 ) ) | 
						
							| 5 |  | hicl | ⊢ ( ( 𝑥  ∈   ℋ  ∧  𝐴  ∈   ℋ )  →  ( 𝑥  ·ih  𝐴 )  ∈  ℂ ) | 
						
							| 6 | 5 | ancoms | ⊢ ( ( 𝐴  ∈   ℋ  ∧  𝑥  ∈   ℋ )  →  ( 𝑥  ·ih  𝐴 )  ∈  ℂ ) | 
						
							| 7 | 6 | div1d | ⊢ ( ( 𝐴  ∈   ℋ  ∧  𝑥  ∈   ℋ )  →  ( ( 𝑥  ·ih  𝐴 )  /  1 )  =  ( 𝑥  ·ih  𝐴 ) ) | 
						
							| 8 | 4 7 | sylan9eqr | ⊢ ( ( ( 𝐴  ∈   ℋ  ∧  𝑥  ∈   ℋ )  ∧  ( normℎ ‘ 𝐴 )  =  1 )  →  ( ( 𝑥  ·ih  𝐴 )  /  ( ( normℎ ‘ 𝐴 ) ↑ 2 ) )  =  ( 𝑥  ·ih  𝐴 ) ) | 
						
							| 9 | 8 | an32s | ⊢ ( ( ( 𝐴  ∈   ℋ  ∧  ( normℎ ‘ 𝐴 )  =  1 )  ∧  𝑥  ∈   ℋ )  →  ( ( 𝑥  ·ih  𝐴 )  /  ( ( normℎ ‘ 𝐴 ) ↑ 2 ) )  =  ( 𝑥  ·ih  𝐴 ) ) | 
						
							| 10 | 9 | oveq1d | ⊢ ( ( ( 𝐴  ∈   ℋ  ∧  ( normℎ ‘ 𝐴 )  =  1 )  ∧  𝑥  ∈   ℋ )  →  ( ( ( 𝑥  ·ih  𝐴 )  /  ( ( normℎ ‘ 𝐴 ) ↑ 2 ) )  ·ℎ  𝐴 )  =  ( ( 𝑥  ·ih  𝐴 )  ·ℎ  𝐴 ) ) | 
						
							| 11 |  | simpll | ⊢ ( ( ( 𝐴  ∈   ℋ  ∧  ( normℎ ‘ 𝐴 )  =  1 )  ∧  𝑥  ∈   ℋ )  →  𝐴  ∈   ℋ ) | 
						
							| 12 |  | simpr | ⊢ ( ( ( 𝐴  ∈   ℋ  ∧  ( normℎ ‘ 𝐴 )  =  1 )  ∧  𝑥  ∈   ℋ )  →  𝑥  ∈   ℋ ) | 
						
							| 13 |  | ax-1ne0 | ⊢ 1  ≠  0 | 
						
							| 14 |  | neeq1 | ⊢ ( ( normℎ ‘ 𝐴 )  =  1  →  ( ( normℎ ‘ 𝐴 )  ≠  0  ↔  1  ≠  0 ) ) | 
						
							| 15 | 13 14 | mpbiri | ⊢ ( ( normℎ ‘ 𝐴 )  =  1  →  ( normℎ ‘ 𝐴 )  ≠  0 ) | 
						
							| 16 |  | normne0 | ⊢ ( 𝐴  ∈   ℋ  →  ( ( normℎ ‘ 𝐴 )  ≠  0  ↔  𝐴  ≠  0ℎ ) ) | 
						
							| 17 | 15 16 | imbitrid | ⊢ ( 𝐴  ∈   ℋ  →  ( ( normℎ ‘ 𝐴 )  =  1  →  𝐴  ≠  0ℎ ) ) | 
						
							| 18 | 17 | imp | ⊢ ( ( 𝐴  ∈   ℋ  ∧  ( normℎ ‘ 𝐴 )  =  1 )  →  𝐴  ≠  0ℎ ) | 
						
							| 19 | 18 | adantr | ⊢ ( ( ( 𝐴  ∈   ℋ  ∧  ( normℎ ‘ 𝐴 )  =  1 )  ∧  𝑥  ∈   ℋ )  →  𝐴  ≠  0ℎ ) | 
						
							| 20 |  | pjspansn | ⊢ ( ( 𝐴  ∈   ℋ  ∧  𝑥  ∈   ℋ  ∧  𝐴  ≠  0ℎ )  →  ( ( projℎ ‘ ( span ‘ { 𝐴 } ) ) ‘ 𝑥 )  =  ( ( ( 𝑥  ·ih  𝐴 )  /  ( ( normℎ ‘ 𝐴 ) ↑ 2 ) )  ·ℎ  𝐴 ) ) | 
						
							| 21 | 11 12 19 20 | syl3anc | ⊢ ( ( ( 𝐴  ∈   ℋ  ∧  ( normℎ ‘ 𝐴 )  =  1 )  ∧  𝑥  ∈   ℋ )  →  ( ( projℎ ‘ ( span ‘ { 𝐴 } ) ) ‘ 𝑥 )  =  ( ( ( 𝑥  ·ih  𝐴 )  /  ( ( normℎ ‘ 𝐴 ) ↑ 2 ) )  ·ℎ  𝐴 ) ) | 
						
							| 22 |  | kbval | ⊢ ( ( 𝐴  ∈   ℋ  ∧  𝐴  ∈   ℋ  ∧  𝑥  ∈   ℋ )  →  ( ( 𝐴  ketbra  𝐴 ) ‘ 𝑥 )  =  ( ( 𝑥  ·ih  𝐴 )  ·ℎ  𝐴 ) ) | 
						
							| 23 | 22 | 3anidm12 | ⊢ ( ( 𝐴  ∈   ℋ  ∧  𝑥  ∈   ℋ )  →  ( ( 𝐴  ketbra  𝐴 ) ‘ 𝑥 )  =  ( ( 𝑥  ·ih  𝐴 )  ·ℎ  𝐴 ) ) | 
						
							| 24 | 23 | adantlr | ⊢ ( ( ( 𝐴  ∈   ℋ  ∧  ( normℎ ‘ 𝐴 )  =  1 )  ∧  𝑥  ∈   ℋ )  →  ( ( 𝐴  ketbra  𝐴 ) ‘ 𝑥 )  =  ( ( 𝑥  ·ih  𝐴 )  ·ℎ  𝐴 ) ) | 
						
							| 25 | 10 21 24 | 3eqtr4rd | ⊢ ( ( ( 𝐴  ∈   ℋ  ∧  ( normℎ ‘ 𝐴 )  =  1 )  ∧  𝑥  ∈   ℋ )  →  ( ( 𝐴  ketbra  𝐴 ) ‘ 𝑥 )  =  ( ( projℎ ‘ ( span ‘ { 𝐴 } ) ) ‘ 𝑥 ) ) | 
						
							| 26 | 25 | ralrimiva | ⊢ ( ( 𝐴  ∈   ℋ  ∧  ( normℎ ‘ 𝐴 )  =  1 )  →  ∀ 𝑥  ∈   ℋ ( ( 𝐴  ketbra  𝐴 ) ‘ 𝑥 )  =  ( ( projℎ ‘ ( span ‘ { 𝐴 } ) ) ‘ 𝑥 ) ) | 
						
							| 27 |  | kbop | ⊢ ( ( 𝐴  ∈   ℋ  ∧  𝐴  ∈   ℋ )  →  ( 𝐴  ketbra  𝐴 ) :  ℋ ⟶  ℋ ) | 
						
							| 28 | 27 | anidms | ⊢ ( 𝐴  ∈   ℋ  →  ( 𝐴  ketbra  𝐴 ) :  ℋ ⟶  ℋ ) | 
						
							| 29 | 28 | ffnd | ⊢ ( 𝐴  ∈   ℋ  →  ( 𝐴  ketbra  𝐴 )  Fn   ℋ ) | 
						
							| 30 |  | spansnch | ⊢ ( 𝐴  ∈   ℋ  →  ( span ‘ { 𝐴 } )  ∈   Cℋ  ) | 
						
							| 31 |  | pjfn | ⊢ ( ( span ‘ { 𝐴 } )  ∈   Cℋ   →  ( projℎ ‘ ( span ‘ { 𝐴 } ) )  Fn   ℋ ) | 
						
							| 32 | 30 31 | syl | ⊢ ( 𝐴  ∈   ℋ  →  ( projℎ ‘ ( span ‘ { 𝐴 } ) )  Fn   ℋ ) | 
						
							| 33 |  | eqfnfv | ⊢ ( ( ( 𝐴  ketbra  𝐴 )  Fn   ℋ  ∧  ( projℎ ‘ ( span ‘ { 𝐴 } ) )  Fn   ℋ )  →  ( ( 𝐴  ketbra  𝐴 )  =  ( projℎ ‘ ( span ‘ { 𝐴 } ) )  ↔  ∀ 𝑥  ∈   ℋ ( ( 𝐴  ketbra  𝐴 ) ‘ 𝑥 )  =  ( ( projℎ ‘ ( span ‘ { 𝐴 } ) ) ‘ 𝑥 ) ) ) | 
						
							| 34 | 29 32 33 | syl2anc | ⊢ ( 𝐴  ∈   ℋ  →  ( ( 𝐴  ketbra  𝐴 )  =  ( projℎ ‘ ( span ‘ { 𝐴 } ) )  ↔  ∀ 𝑥  ∈   ℋ ( ( 𝐴  ketbra  𝐴 ) ‘ 𝑥 )  =  ( ( projℎ ‘ ( span ‘ { 𝐴 } ) ) ‘ 𝑥 ) ) ) | 
						
							| 35 | 34 | adantr | ⊢ ( ( 𝐴  ∈   ℋ  ∧  ( normℎ ‘ 𝐴 )  =  1 )  →  ( ( 𝐴  ketbra  𝐴 )  =  ( projℎ ‘ ( span ‘ { 𝐴 } ) )  ↔  ∀ 𝑥  ∈   ℋ ( ( 𝐴  ketbra  𝐴 ) ‘ 𝑥 )  =  ( ( projℎ ‘ ( span ‘ { 𝐴 } ) ) ‘ 𝑥 ) ) ) | 
						
							| 36 | 26 35 | mpbird | ⊢ ( ( 𝐴  ∈   ℋ  ∧  ( normℎ ‘ 𝐴 )  =  1 )  →  ( 𝐴  ketbra  𝐴 )  =  ( projℎ ‘ ( span ‘ { 𝐴 } ) ) ) |