| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							omlsi.1 | 
							⊢ 𝐴  ∈   Cℋ   | 
						
						
							| 2 | 
							
								
							 | 
							omlsi.2 | 
							⊢ 𝐵  ∈   Sℋ   | 
						
						
							| 3 | 
							
								
							 | 
							omlsi.3 | 
							⊢ 𝐴  ⊆  𝐵  | 
						
						
							| 4 | 
							
								
							 | 
							omlsi.4 | 
							⊢ ( 𝐵  ∩  ( ⊥ ‘ 𝐴 ) )  =  0ℋ  | 
						
						
							| 5 | 
							
								2
							 | 
							sheli | 
							⊢ ( 𝑥  ∈  𝐵  →  𝑥  ∈   ℋ )  | 
						
						
							| 6 | 
							
								1 5
							 | 
							pjhthlem2 | 
							⊢ ( 𝑥  ∈  𝐵  →  ∃ 𝑦  ∈  𝐴 ∃ 𝑧  ∈  ( ⊥ ‘ 𝐴 ) 𝑥  =  ( 𝑦  +ℎ  𝑧 ) )  | 
						
						
							| 7 | 
							
								
							 | 
							eqeq1 | 
							⊢ ( 𝑥  =  if ( 𝑥  ∈  𝐵 ,  𝑥 ,  0ℎ )  →  ( 𝑥  =  ( 𝑦  +ℎ  𝑧 )  ↔  if ( 𝑥  ∈  𝐵 ,  𝑥 ,  0ℎ )  =  ( 𝑦  +ℎ  𝑧 ) ) )  | 
						
						
							| 8 | 
							
								
							 | 
							eleq1 | 
							⊢ ( 𝑥  =  if ( 𝑥  ∈  𝐵 ,  𝑥 ,  0ℎ )  →  ( 𝑥  ∈  𝐴  ↔  if ( 𝑥  ∈  𝐵 ,  𝑥 ,  0ℎ )  ∈  𝐴 ) )  | 
						
						
							| 9 | 
							
								7 8
							 | 
							imbi12d | 
							⊢ ( 𝑥  =  if ( 𝑥  ∈  𝐵 ,  𝑥 ,  0ℎ )  →  ( ( 𝑥  =  ( 𝑦  +ℎ  𝑧 )  →  𝑥  ∈  𝐴 )  ↔  ( if ( 𝑥  ∈  𝐵 ,  𝑥 ,  0ℎ )  =  ( 𝑦  +ℎ  𝑧 )  →  if ( 𝑥  ∈  𝐵 ,  𝑥 ,  0ℎ )  ∈  𝐴 ) ) )  | 
						
						
							| 10 | 
							
								
							 | 
							oveq1 | 
							⊢ ( 𝑦  =  if ( 𝑦  ∈  𝐴 ,  𝑦 ,  0ℎ )  →  ( 𝑦  +ℎ  𝑧 )  =  ( if ( 𝑦  ∈  𝐴 ,  𝑦 ,  0ℎ )  +ℎ  𝑧 ) )  | 
						
						
							| 11 | 
							
								10
							 | 
							eqeq2d | 
							⊢ ( 𝑦  =  if ( 𝑦  ∈  𝐴 ,  𝑦 ,  0ℎ )  →  ( if ( 𝑥  ∈  𝐵 ,  𝑥 ,  0ℎ )  =  ( 𝑦  +ℎ  𝑧 )  ↔  if ( 𝑥  ∈  𝐵 ,  𝑥 ,  0ℎ )  =  ( if ( 𝑦  ∈  𝐴 ,  𝑦 ,  0ℎ )  +ℎ  𝑧 ) ) )  | 
						
						
							| 12 | 
							
								11
							 | 
							imbi1d | 
							⊢ ( 𝑦  =  if ( 𝑦  ∈  𝐴 ,  𝑦 ,  0ℎ )  →  ( ( if ( 𝑥  ∈  𝐵 ,  𝑥 ,  0ℎ )  =  ( 𝑦  +ℎ  𝑧 )  →  if ( 𝑥  ∈  𝐵 ,  𝑥 ,  0ℎ )  ∈  𝐴 )  ↔  ( if ( 𝑥  ∈  𝐵 ,  𝑥 ,  0ℎ )  =  ( if ( 𝑦  ∈  𝐴 ,  𝑦 ,  0ℎ )  +ℎ  𝑧 )  →  if ( 𝑥  ∈  𝐵 ,  𝑥 ,  0ℎ )  ∈  𝐴 ) ) )  | 
						
						
							| 13 | 
							
								
							 | 
							oveq2 | 
							⊢ ( 𝑧  =  if ( 𝑧  ∈  ( ⊥ ‘ 𝐴 ) ,  𝑧 ,  0ℎ )  →  ( if ( 𝑦  ∈  𝐴 ,  𝑦 ,  0ℎ )  +ℎ  𝑧 )  =  ( if ( 𝑦  ∈  𝐴 ,  𝑦 ,  0ℎ )  +ℎ  if ( 𝑧  ∈  ( ⊥ ‘ 𝐴 ) ,  𝑧 ,  0ℎ ) ) )  | 
						
						
							| 14 | 
							
								13
							 | 
							eqeq2d | 
							⊢ ( 𝑧  =  if ( 𝑧  ∈  ( ⊥ ‘ 𝐴 ) ,  𝑧 ,  0ℎ )  →  ( if ( 𝑥  ∈  𝐵 ,  𝑥 ,  0ℎ )  =  ( if ( 𝑦  ∈  𝐴 ,  𝑦 ,  0ℎ )  +ℎ  𝑧 )  ↔  if ( 𝑥  ∈  𝐵 ,  𝑥 ,  0ℎ )  =  ( if ( 𝑦  ∈  𝐴 ,  𝑦 ,  0ℎ )  +ℎ  if ( 𝑧  ∈  ( ⊥ ‘ 𝐴 ) ,  𝑧 ,  0ℎ ) ) ) )  | 
						
						
							| 15 | 
							
								14
							 | 
							imbi1d | 
							⊢ ( 𝑧  =  if ( 𝑧  ∈  ( ⊥ ‘ 𝐴 ) ,  𝑧 ,  0ℎ )  →  ( ( if ( 𝑥  ∈  𝐵 ,  𝑥 ,  0ℎ )  =  ( if ( 𝑦  ∈  𝐴 ,  𝑦 ,  0ℎ )  +ℎ  𝑧 )  →  if ( 𝑥  ∈  𝐵 ,  𝑥 ,  0ℎ )  ∈  𝐴 )  ↔  ( if ( 𝑥  ∈  𝐵 ,  𝑥 ,  0ℎ )  =  ( if ( 𝑦  ∈  𝐴 ,  𝑦 ,  0ℎ )  +ℎ  if ( 𝑧  ∈  ( ⊥ ‘ 𝐴 ) ,  𝑧 ,  0ℎ ) )  →  if ( 𝑥  ∈  𝐵 ,  𝑥 ,  0ℎ )  ∈  𝐴 ) ) )  | 
						
						
							| 16 | 
							
								1
							 | 
							chshii | 
							⊢ 𝐴  ∈   Sℋ   | 
						
						
							| 17 | 
							
								
							 | 
							sh0 | 
							⊢ ( 𝐵  ∈   Sℋ   →  0ℎ  ∈  𝐵 )  | 
						
						
							| 18 | 
							
								2 17
							 | 
							ax-mp | 
							⊢ 0ℎ  ∈  𝐵  | 
						
						
							| 19 | 
							
								18
							 | 
							elimel | 
							⊢ if ( 𝑥  ∈  𝐵 ,  𝑥 ,  0ℎ )  ∈  𝐵  | 
						
						
							| 20 | 
							
								
							 | 
							ch0 | 
							⊢ ( 𝐴  ∈   Cℋ   →  0ℎ  ∈  𝐴 )  | 
						
						
							| 21 | 
							
								1 20
							 | 
							ax-mp | 
							⊢ 0ℎ  ∈  𝐴  | 
						
						
							| 22 | 
							
								21
							 | 
							elimel | 
							⊢ if ( 𝑦  ∈  𝐴 ,  𝑦 ,  0ℎ )  ∈  𝐴  | 
						
						
							| 23 | 
							
								
							 | 
							shocsh | 
							⊢ ( 𝐴  ∈   Sℋ   →  ( ⊥ ‘ 𝐴 )  ∈   Sℋ  )  | 
						
						
							| 24 | 
							
								16 23
							 | 
							ax-mp | 
							⊢ ( ⊥ ‘ 𝐴 )  ∈   Sℋ   | 
						
						
							| 25 | 
							
								
							 | 
							sh0 | 
							⊢ ( ( ⊥ ‘ 𝐴 )  ∈   Sℋ   →  0ℎ  ∈  ( ⊥ ‘ 𝐴 ) )  | 
						
						
							| 26 | 
							
								24 25
							 | 
							ax-mp | 
							⊢ 0ℎ  ∈  ( ⊥ ‘ 𝐴 )  | 
						
						
							| 27 | 
							
								26
							 | 
							elimel | 
							⊢ if ( 𝑧  ∈  ( ⊥ ‘ 𝐴 ) ,  𝑧 ,  0ℎ )  ∈  ( ⊥ ‘ 𝐴 )  | 
						
						
							| 28 | 
							
								16 2 3 4 19 22 27
							 | 
							omlsilem | 
							⊢ ( if ( 𝑥  ∈  𝐵 ,  𝑥 ,  0ℎ )  =  ( if ( 𝑦  ∈  𝐴 ,  𝑦 ,  0ℎ )  +ℎ  if ( 𝑧  ∈  ( ⊥ ‘ 𝐴 ) ,  𝑧 ,  0ℎ ) )  →  if ( 𝑥  ∈  𝐵 ,  𝑥 ,  0ℎ )  ∈  𝐴 )  | 
						
						
							| 29 | 
							
								9 12 15 28
							 | 
							dedth3h | 
							⊢ ( ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐴  ∧  𝑧  ∈  ( ⊥ ‘ 𝐴 ) )  →  ( 𝑥  =  ( 𝑦  +ℎ  𝑧 )  →  𝑥  ∈  𝐴 ) )  | 
						
						
							| 30 | 
							
								29
							 | 
							3expia | 
							⊢ ( ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐴 )  →  ( 𝑧  ∈  ( ⊥ ‘ 𝐴 )  →  ( 𝑥  =  ( 𝑦  +ℎ  𝑧 )  →  𝑥  ∈  𝐴 ) ) )  | 
						
						
							| 31 | 
							
								30
							 | 
							rexlimdv | 
							⊢ ( ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐴 )  →  ( ∃ 𝑧  ∈  ( ⊥ ‘ 𝐴 ) 𝑥  =  ( 𝑦  +ℎ  𝑧 )  →  𝑥  ∈  𝐴 ) )  | 
						
						
							| 32 | 
							
								31
							 | 
							rexlimdva | 
							⊢ ( 𝑥  ∈  𝐵  →  ( ∃ 𝑦  ∈  𝐴 ∃ 𝑧  ∈  ( ⊥ ‘ 𝐴 ) 𝑥  =  ( 𝑦  +ℎ  𝑧 )  →  𝑥  ∈  𝐴 ) )  | 
						
						
							| 33 | 
							
								6 32
							 | 
							mpd | 
							⊢ ( 𝑥  ∈  𝐵  →  𝑥  ∈  𝐴 )  | 
						
						
							| 34 | 
							
								33
							 | 
							ssriv | 
							⊢ 𝐵  ⊆  𝐴  | 
						
						
							| 35 | 
							
								3 34
							 | 
							eqssi | 
							⊢ 𝐴  =  𝐵  |