| Step | Hyp | Ref | Expression | 
						
							| 1 |  | lsmcntz.p | ⊢  ⊕   =  ( LSSum ‘ 𝐺 ) | 
						
							| 2 |  | lsmcntz.s | ⊢ ( 𝜑  →  𝑆  ∈  ( SubGrp ‘ 𝐺 ) ) | 
						
							| 3 |  | lsmcntz.t | ⊢ ( 𝜑  →  𝑇  ∈  ( SubGrp ‘ 𝐺 ) ) | 
						
							| 4 |  | lsmcntz.u | ⊢ ( 𝜑  →  𝑈  ∈  ( SubGrp ‘ 𝐺 ) ) | 
						
							| 5 |  | lsmdisj.o | ⊢  0   =  ( 0g ‘ 𝐺 ) | 
						
							| 6 | 2 | adantr | ⊢ ( ( 𝜑  ∧  ( ( ( 𝑆  ⊕  𝑇 )  ∩  𝑈 )  =  {  0  }  ∧  ( 𝑆  ∩  𝑇 )  =  {  0  } ) )  →  𝑆  ∈  ( SubGrp ‘ 𝐺 ) ) | 
						
							| 7 | 3 | adantr | ⊢ ( ( 𝜑  ∧  ( ( ( 𝑆  ⊕  𝑇 )  ∩  𝑈 )  =  {  0  }  ∧  ( 𝑆  ∩  𝑇 )  =  {  0  } ) )  →  𝑇  ∈  ( SubGrp ‘ 𝐺 ) ) | 
						
							| 8 | 4 | adantr | ⊢ ( ( 𝜑  ∧  ( ( ( 𝑆  ⊕  𝑇 )  ∩  𝑈 )  =  {  0  }  ∧  ( 𝑆  ∩  𝑇 )  =  {  0  } ) )  →  𝑈  ∈  ( SubGrp ‘ 𝐺 ) ) | 
						
							| 9 |  | simprl | ⊢ ( ( 𝜑  ∧  ( ( ( 𝑆  ⊕  𝑇 )  ∩  𝑈 )  =  {  0  }  ∧  ( 𝑆  ∩  𝑇 )  =  {  0  } ) )  →  ( ( 𝑆  ⊕  𝑇 )  ∩  𝑈 )  =  {  0  } ) | 
						
							| 10 |  | simprr | ⊢ ( ( 𝜑  ∧  ( ( ( 𝑆  ⊕  𝑇 )  ∩  𝑈 )  =  {  0  }  ∧  ( 𝑆  ∩  𝑇 )  =  {  0  } ) )  →  ( 𝑆  ∩  𝑇 )  =  {  0  } ) | 
						
							| 11 | 1 6 7 8 5 9 10 | lsmdisj2 | ⊢ ( ( 𝜑  ∧  ( ( ( 𝑆  ⊕  𝑇 )  ∩  𝑈 )  =  {  0  }  ∧  ( 𝑆  ∩  𝑇 )  =  {  0  } ) )  →  ( 𝑇  ∩  ( 𝑆  ⊕  𝑈 ) )  =  {  0  } ) | 
						
							| 12 | 1 6 7 8 5 9 | lsmdisj | ⊢ ( ( 𝜑  ∧  ( ( ( 𝑆  ⊕  𝑇 )  ∩  𝑈 )  =  {  0  }  ∧  ( 𝑆  ∩  𝑇 )  =  {  0  } ) )  →  ( ( 𝑆  ∩  𝑈 )  =  {  0  }  ∧  ( 𝑇  ∩  𝑈 )  =  {  0  } ) ) | 
						
							| 13 | 12 | simpld | ⊢ ( ( 𝜑  ∧  ( ( ( 𝑆  ⊕  𝑇 )  ∩  𝑈 )  =  {  0  }  ∧  ( 𝑆  ∩  𝑇 )  =  {  0  } ) )  →  ( 𝑆  ∩  𝑈 )  =  {  0  } ) | 
						
							| 14 | 11 13 | jca | ⊢ ( ( 𝜑  ∧  ( ( ( 𝑆  ⊕  𝑇 )  ∩  𝑈 )  =  {  0  }  ∧  ( 𝑆  ∩  𝑇 )  =  {  0  } ) )  →  ( ( 𝑇  ∩  ( 𝑆  ⊕  𝑈 ) )  =  {  0  }  ∧  ( 𝑆  ∩  𝑈 )  =  {  0  } ) ) | 
						
							| 15 |  | incom | ⊢ ( ( 𝑆  ⊕  𝑇 )  ∩  𝑈 )  =  ( 𝑈  ∩  ( 𝑆  ⊕  𝑇 ) ) | 
						
							| 16 | 2 | adantr | ⊢ ( ( 𝜑  ∧  ( ( 𝑇  ∩  ( 𝑆  ⊕  𝑈 ) )  =  {  0  }  ∧  ( 𝑆  ∩  𝑈 )  =  {  0  } ) )  →  𝑆  ∈  ( SubGrp ‘ 𝐺 ) ) | 
						
							| 17 | 4 | adantr | ⊢ ( ( 𝜑  ∧  ( ( 𝑇  ∩  ( 𝑆  ⊕  𝑈 ) )  =  {  0  }  ∧  ( 𝑆  ∩  𝑈 )  =  {  0  } ) )  →  𝑈  ∈  ( SubGrp ‘ 𝐺 ) ) | 
						
							| 18 | 3 | adantr | ⊢ ( ( 𝜑  ∧  ( ( 𝑇  ∩  ( 𝑆  ⊕  𝑈 ) )  =  {  0  }  ∧  ( 𝑆  ∩  𝑈 )  =  {  0  } ) )  →  𝑇  ∈  ( SubGrp ‘ 𝐺 ) ) | 
						
							| 19 |  | incom | ⊢ ( ( 𝑆  ⊕  𝑈 )  ∩  𝑇 )  =  ( 𝑇  ∩  ( 𝑆  ⊕  𝑈 ) ) | 
						
							| 20 |  | simprl | ⊢ ( ( 𝜑  ∧  ( ( 𝑇  ∩  ( 𝑆  ⊕  𝑈 ) )  =  {  0  }  ∧  ( 𝑆  ∩  𝑈 )  =  {  0  } ) )  →  ( 𝑇  ∩  ( 𝑆  ⊕  𝑈 ) )  =  {  0  } ) | 
						
							| 21 | 19 20 | eqtrid | ⊢ ( ( 𝜑  ∧  ( ( 𝑇  ∩  ( 𝑆  ⊕  𝑈 ) )  =  {  0  }  ∧  ( 𝑆  ∩  𝑈 )  =  {  0  } ) )  →  ( ( 𝑆  ⊕  𝑈 )  ∩  𝑇 )  =  {  0  } ) | 
						
							| 22 |  | simprr | ⊢ ( ( 𝜑  ∧  ( ( 𝑇  ∩  ( 𝑆  ⊕  𝑈 ) )  =  {  0  }  ∧  ( 𝑆  ∩  𝑈 )  =  {  0  } ) )  →  ( 𝑆  ∩  𝑈 )  =  {  0  } ) | 
						
							| 23 | 1 16 17 18 5 21 22 | lsmdisj2 | ⊢ ( ( 𝜑  ∧  ( ( 𝑇  ∩  ( 𝑆  ⊕  𝑈 ) )  =  {  0  }  ∧  ( 𝑆  ∩  𝑈 )  =  {  0  } ) )  →  ( 𝑈  ∩  ( 𝑆  ⊕  𝑇 ) )  =  {  0  } ) | 
						
							| 24 | 15 23 | eqtrid | ⊢ ( ( 𝜑  ∧  ( ( 𝑇  ∩  ( 𝑆  ⊕  𝑈 ) )  =  {  0  }  ∧  ( 𝑆  ∩  𝑈 )  =  {  0  } ) )  →  ( ( 𝑆  ⊕  𝑇 )  ∩  𝑈 )  =  {  0  } ) | 
						
							| 25 |  | incom | ⊢ ( 𝑆  ∩  𝑇 )  =  ( 𝑇  ∩  𝑆 ) | 
						
							| 26 | 1 18 16 17 5 20 | lsmdisjr | ⊢ ( ( 𝜑  ∧  ( ( 𝑇  ∩  ( 𝑆  ⊕  𝑈 ) )  =  {  0  }  ∧  ( 𝑆  ∩  𝑈 )  =  {  0  } ) )  →  ( ( 𝑇  ∩  𝑆 )  =  {  0  }  ∧  ( 𝑇  ∩  𝑈 )  =  {  0  } ) ) | 
						
							| 27 | 26 | simpld | ⊢ ( ( 𝜑  ∧  ( ( 𝑇  ∩  ( 𝑆  ⊕  𝑈 ) )  =  {  0  }  ∧  ( 𝑆  ∩  𝑈 )  =  {  0  } ) )  →  ( 𝑇  ∩  𝑆 )  =  {  0  } ) | 
						
							| 28 | 25 27 | eqtrid | ⊢ ( ( 𝜑  ∧  ( ( 𝑇  ∩  ( 𝑆  ⊕  𝑈 ) )  =  {  0  }  ∧  ( 𝑆  ∩  𝑈 )  =  {  0  } ) )  →  ( 𝑆  ∩  𝑇 )  =  {  0  } ) | 
						
							| 29 | 24 28 | jca | ⊢ ( ( 𝜑  ∧  ( ( 𝑇  ∩  ( 𝑆  ⊕  𝑈 ) )  =  {  0  }  ∧  ( 𝑆  ∩  𝑈 )  =  {  0  } ) )  →  ( ( ( 𝑆  ⊕  𝑇 )  ∩  𝑈 )  =  {  0  }  ∧  ( 𝑆  ∩  𝑇 )  =  {  0  } ) ) | 
						
							| 30 | 14 29 | impbida | ⊢ ( 𝜑  →  ( ( ( ( 𝑆  ⊕  𝑇 )  ∩  𝑈 )  =  {  0  }  ∧  ( 𝑆  ∩  𝑇 )  =  {  0  } )  ↔  ( ( 𝑇  ∩  ( 𝑆  ⊕  𝑈 ) )  =  {  0  }  ∧  ( 𝑆  ∩  𝑈 )  =  {  0  } ) ) ) |