| Step | Hyp | Ref | Expression | 
						
							| 1 |  | hvmulcl | ⊢ ( ( 𝐴  ∈  ℂ  ∧  𝐶  ∈   ℋ )  →  ( 𝐴  ·ℎ  𝐶 )  ∈   ℋ ) | 
						
							| 2 | 1 | 3adant2 | ⊢ ( ( 𝐴  ∈  ℂ  ∧  𝐵  ∈  ℂ  ∧  𝐶  ∈   ℋ )  →  ( 𝐴  ·ℎ  𝐶 )  ∈   ℋ ) | 
						
							| 3 |  | hvmulcl | ⊢ ( ( 𝐵  ∈  ℂ  ∧  𝐶  ∈   ℋ )  →  ( 𝐵  ·ℎ  𝐶 )  ∈   ℋ ) | 
						
							| 4 | 3 | 3adant1 | ⊢ ( ( 𝐴  ∈  ℂ  ∧  𝐵  ∈  ℂ  ∧  𝐶  ∈   ℋ )  →  ( 𝐵  ·ℎ  𝐶 )  ∈   ℋ ) | 
						
							| 5 |  | hvsubval | ⊢ ( ( ( 𝐴  ·ℎ  𝐶 )  ∈   ℋ  ∧  ( 𝐵  ·ℎ  𝐶 )  ∈   ℋ )  →  ( ( 𝐴  ·ℎ  𝐶 )  −ℎ  ( 𝐵  ·ℎ  𝐶 ) )  =  ( ( 𝐴  ·ℎ  𝐶 )  +ℎ  ( - 1  ·ℎ  ( 𝐵  ·ℎ  𝐶 ) ) ) ) | 
						
							| 6 | 2 4 5 | syl2anc | ⊢ ( ( 𝐴  ∈  ℂ  ∧  𝐵  ∈  ℂ  ∧  𝐶  ∈   ℋ )  →  ( ( 𝐴  ·ℎ  𝐶 )  −ℎ  ( 𝐵  ·ℎ  𝐶 ) )  =  ( ( 𝐴  ·ℎ  𝐶 )  +ℎ  ( - 1  ·ℎ  ( 𝐵  ·ℎ  𝐶 ) ) ) ) | 
						
							| 7 |  | mulm1 | ⊢ ( 𝐵  ∈  ℂ  →  ( - 1  ·  𝐵 )  =  - 𝐵 ) | 
						
							| 8 | 7 | oveq1d | ⊢ ( 𝐵  ∈  ℂ  →  ( ( - 1  ·  𝐵 )  ·ℎ  𝐶 )  =  ( - 𝐵  ·ℎ  𝐶 ) ) | 
						
							| 9 | 8 | adantr | ⊢ ( ( 𝐵  ∈  ℂ  ∧  𝐶  ∈   ℋ )  →  ( ( - 1  ·  𝐵 )  ·ℎ  𝐶 )  =  ( - 𝐵  ·ℎ  𝐶 ) ) | 
						
							| 10 |  | neg1cn | ⊢ - 1  ∈  ℂ | 
						
							| 11 |  | ax-hvmulass | ⊢ ( ( - 1  ∈  ℂ  ∧  𝐵  ∈  ℂ  ∧  𝐶  ∈   ℋ )  →  ( ( - 1  ·  𝐵 )  ·ℎ  𝐶 )  =  ( - 1  ·ℎ  ( 𝐵  ·ℎ  𝐶 ) ) ) | 
						
							| 12 | 10 11 | mp3an1 | ⊢ ( ( 𝐵  ∈  ℂ  ∧  𝐶  ∈   ℋ )  →  ( ( - 1  ·  𝐵 )  ·ℎ  𝐶 )  =  ( - 1  ·ℎ  ( 𝐵  ·ℎ  𝐶 ) ) ) | 
						
							| 13 | 9 12 | eqtr3d | ⊢ ( ( 𝐵  ∈  ℂ  ∧  𝐶  ∈   ℋ )  →  ( - 𝐵  ·ℎ  𝐶 )  =  ( - 1  ·ℎ  ( 𝐵  ·ℎ  𝐶 ) ) ) | 
						
							| 14 | 13 | 3adant1 | ⊢ ( ( 𝐴  ∈  ℂ  ∧  𝐵  ∈  ℂ  ∧  𝐶  ∈   ℋ )  →  ( - 𝐵  ·ℎ  𝐶 )  =  ( - 1  ·ℎ  ( 𝐵  ·ℎ  𝐶 ) ) ) | 
						
							| 15 | 14 | oveq2d | ⊢ ( ( 𝐴  ∈  ℂ  ∧  𝐵  ∈  ℂ  ∧  𝐶  ∈   ℋ )  →  ( ( 𝐴  ·ℎ  𝐶 )  +ℎ  ( - 𝐵  ·ℎ  𝐶 ) )  =  ( ( 𝐴  ·ℎ  𝐶 )  +ℎ  ( - 1  ·ℎ  ( 𝐵  ·ℎ  𝐶 ) ) ) ) | 
						
							| 16 |  | negcl | ⊢ ( 𝐵  ∈  ℂ  →  - 𝐵  ∈  ℂ ) | 
						
							| 17 |  | ax-hvdistr2 | ⊢ ( ( 𝐴  ∈  ℂ  ∧  - 𝐵  ∈  ℂ  ∧  𝐶  ∈   ℋ )  →  ( ( 𝐴  +  - 𝐵 )  ·ℎ  𝐶 )  =  ( ( 𝐴  ·ℎ  𝐶 )  +ℎ  ( - 𝐵  ·ℎ  𝐶 ) ) ) | 
						
							| 18 | 16 17 | syl3an2 | ⊢ ( ( 𝐴  ∈  ℂ  ∧  𝐵  ∈  ℂ  ∧  𝐶  ∈   ℋ )  →  ( ( 𝐴  +  - 𝐵 )  ·ℎ  𝐶 )  =  ( ( 𝐴  ·ℎ  𝐶 )  +ℎ  ( - 𝐵  ·ℎ  𝐶 ) ) ) | 
						
							| 19 |  | negsub | ⊢ ( ( 𝐴  ∈  ℂ  ∧  𝐵  ∈  ℂ )  →  ( 𝐴  +  - 𝐵 )  =  ( 𝐴  −  𝐵 ) ) | 
						
							| 20 | 19 | 3adant3 | ⊢ ( ( 𝐴  ∈  ℂ  ∧  𝐵  ∈  ℂ  ∧  𝐶  ∈   ℋ )  →  ( 𝐴  +  - 𝐵 )  =  ( 𝐴  −  𝐵 ) ) | 
						
							| 21 | 20 | oveq1d | ⊢ ( ( 𝐴  ∈  ℂ  ∧  𝐵  ∈  ℂ  ∧  𝐶  ∈   ℋ )  →  ( ( 𝐴  +  - 𝐵 )  ·ℎ  𝐶 )  =  ( ( 𝐴  −  𝐵 )  ·ℎ  𝐶 ) ) | 
						
							| 22 | 18 21 | eqtr3d | ⊢ ( ( 𝐴  ∈  ℂ  ∧  𝐵  ∈  ℂ  ∧  𝐶  ∈   ℋ )  →  ( ( 𝐴  ·ℎ  𝐶 )  +ℎ  ( - 𝐵  ·ℎ  𝐶 ) )  =  ( ( 𝐴  −  𝐵 )  ·ℎ  𝐶 ) ) | 
						
							| 23 | 6 15 22 | 3eqtr2rd | ⊢ ( ( 𝐴  ∈  ℂ  ∧  𝐵  ∈  ℂ  ∧  𝐶  ∈   ℋ )  →  ( ( 𝐴  −  𝐵 )  ·ℎ  𝐶 )  =  ( ( 𝐴  ·ℎ  𝐶 )  −ℎ  ( 𝐵  ·ℎ  𝐶 ) ) ) |