| Step | Hyp | Ref | Expression | 
						
							| 1 |  | rnglidl0.u | ⊢ 𝑈  =  ( LIdeal ‘ 𝑅 ) | 
						
							| 2 |  | rnglidl0.z | ⊢  0   =  ( 0g ‘ 𝑅 ) | 
						
							| 3 |  | eqid | ⊢ ( Base ‘ 𝑅 )  =  ( Base ‘ 𝑅 ) | 
						
							| 4 | 3 2 | rng0cl | ⊢ ( 𝑅  ∈  Rng  →   0   ∈  ( Base ‘ 𝑅 ) ) | 
						
							| 5 | 4 | snssd | ⊢ ( 𝑅  ∈  Rng  →  {  0  }  ⊆  ( Base ‘ 𝑅 ) ) | 
						
							| 6 | 2 | fvexi | ⊢  0   ∈  V | 
						
							| 7 | 6 | a1i | ⊢ ( 𝑅  ∈  Rng  →   0   ∈  V ) | 
						
							| 8 | 7 | snn0d | ⊢ ( 𝑅  ∈  Rng  →  {  0  }  ≠  ∅ ) | 
						
							| 9 |  | eqid | ⊢ ( .r ‘ 𝑅 )  =  ( .r ‘ 𝑅 ) | 
						
							| 10 | 3 9 2 | rngrz | ⊢ ( ( 𝑅  ∈  Rng  ∧  𝑥  ∈  ( Base ‘ 𝑅 ) )  →  ( 𝑥 ( .r ‘ 𝑅 )  0  )  =   0  ) | 
						
							| 11 | 10 | oveq1d | ⊢ ( ( 𝑅  ∈  Rng  ∧  𝑥  ∈  ( Base ‘ 𝑅 ) )  →  ( ( 𝑥 ( .r ‘ 𝑅 )  0  ) ( +g ‘ 𝑅 )  0  )  =  (  0  ( +g ‘ 𝑅 )  0  ) ) | 
						
							| 12 |  | rnggrp | ⊢ ( 𝑅  ∈  Rng  →  𝑅  ∈  Grp ) | 
						
							| 13 | 3 2 | grpidcl | ⊢ ( 𝑅  ∈  Grp  →   0   ∈  ( Base ‘ 𝑅 ) ) | 
						
							| 14 |  | eqid | ⊢ ( +g ‘ 𝑅 )  =  ( +g ‘ 𝑅 ) | 
						
							| 15 | 3 14 2 | grprid | ⊢ ( ( 𝑅  ∈  Grp  ∧   0   ∈  ( Base ‘ 𝑅 ) )  →  (  0  ( +g ‘ 𝑅 )  0  )  =   0  ) | 
						
							| 16 | 12 13 15 | syl2anc2 | ⊢ ( 𝑅  ∈  Rng  →  (  0  ( +g ‘ 𝑅 )  0  )  =   0  ) | 
						
							| 17 | 16 | adantr | ⊢ ( ( 𝑅  ∈  Rng  ∧  𝑥  ∈  ( Base ‘ 𝑅 ) )  →  (  0  ( +g ‘ 𝑅 )  0  )  =   0  ) | 
						
							| 18 | 11 17 | eqtrd | ⊢ ( ( 𝑅  ∈  Rng  ∧  𝑥  ∈  ( Base ‘ 𝑅 ) )  →  ( ( 𝑥 ( .r ‘ 𝑅 )  0  ) ( +g ‘ 𝑅 )  0  )  =   0  ) | 
						
							| 19 | 6 | elsn2 | ⊢ ( ( ( 𝑥 ( .r ‘ 𝑅 )  0  ) ( +g ‘ 𝑅 )  0  )  ∈  {  0  }  ↔  ( ( 𝑥 ( .r ‘ 𝑅 )  0  ) ( +g ‘ 𝑅 )  0  )  =   0  ) | 
						
							| 20 | 18 19 | sylibr | ⊢ ( ( 𝑅  ∈  Rng  ∧  𝑥  ∈  ( Base ‘ 𝑅 ) )  →  ( ( 𝑥 ( .r ‘ 𝑅 )  0  ) ( +g ‘ 𝑅 )  0  )  ∈  {  0  } ) | 
						
							| 21 |  | oveq2 | ⊢ ( 𝑦  =   0   →  ( 𝑥 ( .r ‘ 𝑅 ) 𝑦 )  =  ( 𝑥 ( .r ‘ 𝑅 )  0  ) ) | 
						
							| 22 | 21 | oveq1d | ⊢ ( 𝑦  =   0   →  ( ( 𝑥 ( .r ‘ 𝑅 ) 𝑦 ) ( +g ‘ 𝑅 ) 𝑧 )  =  ( ( 𝑥 ( .r ‘ 𝑅 )  0  ) ( +g ‘ 𝑅 ) 𝑧 ) ) | 
						
							| 23 | 22 | eleq1d | ⊢ ( 𝑦  =   0   →  ( ( ( 𝑥 ( .r ‘ 𝑅 ) 𝑦 ) ( +g ‘ 𝑅 ) 𝑧 )  ∈  {  0  }  ↔  ( ( 𝑥 ( .r ‘ 𝑅 )  0  ) ( +g ‘ 𝑅 ) 𝑧 )  ∈  {  0  } ) ) | 
						
							| 24 | 23 | ralbidv | ⊢ ( 𝑦  =   0   →  ( ∀ 𝑧  ∈  {  0  } ( ( 𝑥 ( .r ‘ 𝑅 ) 𝑦 ) ( +g ‘ 𝑅 ) 𝑧 )  ∈  {  0  }  ↔  ∀ 𝑧  ∈  {  0  } ( ( 𝑥 ( .r ‘ 𝑅 )  0  ) ( +g ‘ 𝑅 ) 𝑧 )  ∈  {  0  } ) ) | 
						
							| 25 | 6 24 | ralsn | ⊢ ( ∀ 𝑦  ∈  {  0  } ∀ 𝑧  ∈  {  0  } ( ( 𝑥 ( .r ‘ 𝑅 ) 𝑦 ) ( +g ‘ 𝑅 ) 𝑧 )  ∈  {  0  }  ↔  ∀ 𝑧  ∈  {  0  } ( ( 𝑥 ( .r ‘ 𝑅 )  0  ) ( +g ‘ 𝑅 ) 𝑧 )  ∈  {  0  } ) | 
						
							| 26 |  | oveq2 | ⊢ ( 𝑧  =   0   →  ( ( 𝑥 ( .r ‘ 𝑅 )  0  ) ( +g ‘ 𝑅 ) 𝑧 )  =  ( ( 𝑥 ( .r ‘ 𝑅 )  0  ) ( +g ‘ 𝑅 )  0  ) ) | 
						
							| 27 | 26 | eleq1d | ⊢ ( 𝑧  =   0   →  ( ( ( 𝑥 ( .r ‘ 𝑅 )  0  ) ( +g ‘ 𝑅 ) 𝑧 )  ∈  {  0  }  ↔  ( ( 𝑥 ( .r ‘ 𝑅 )  0  ) ( +g ‘ 𝑅 )  0  )  ∈  {  0  } ) ) | 
						
							| 28 | 6 27 | ralsn | ⊢ ( ∀ 𝑧  ∈  {  0  } ( ( 𝑥 ( .r ‘ 𝑅 )  0  ) ( +g ‘ 𝑅 ) 𝑧 )  ∈  {  0  }  ↔  ( ( 𝑥 ( .r ‘ 𝑅 )  0  ) ( +g ‘ 𝑅 )  0  )  ∈  {  0  } ) | 
						
							| 29 | 25 28 | bitri | ⊢ ( ∀ 𝑦  ∈  {  0  } ∀ 𝑧  ∈  {  0  } ( ( 𝑥 ( .r ‘ 𝑅 ) 𝑦 ) ( +g ‘ 𝑅 ) 𝑧 )  ∈  {  0  }  ↔  ( ( 𝑥 ( .r ‘ 𝑅 )  0  ) ( +g ‘ 𝑅 )  0  )  ∈  {  0  } ) | 
						
							| 30 | 20 29 | sylibr | ⊢ ( ( 𝑅  ∈  Rng  ∧  𝑥  ∈  ( Base ‘ 𝑅 ) )  →  ∀ 𝑦  ∈  {  0  } ∀ 𝑧  ∈  {  0  } ( ( 𝑥 ( .r ‘ 𝑅 ) 𝑦 ) ( +g ‘ 𝑅 ) 𝑧 )  ∈  {  0  } ) | 
						
							| 31 | 30 | ralrimiva | ⊢ ( 𝑅  ∈  Rng  →  ∀ 𝑥  ∈  ( Base ‘ 𝑅 ) ∀ 𝑦  ∈  {  0  } ∀ 𝑧  ∈  {  0  } ( ( 𝑥 ( .r ‘ 𝑅 ) 𝑦 ) ( +g ‘ 𝑅 ) 𝑧 )  ∈  {  0  } ) | 
						
							| 32 | 1 3 14 9 | islidl | ⊢ ( {  0  }  ∈  𝑈  ↔  ( {  0  }  ⊆  ( Base ‘ 𝑅 )  ∧  {  0  }  ≠  ∅  ∧  ∀ 𝑥  ∈  ( Base ‘ 𝑅 ) ∀ 𝑦  ∈  {  0  } ∀ 𝑧  ∈  {  0  } ( ( 𝑥 ( .r ‘ 𝑅 ) 𝑦 ) ( +g ‘ 𝑅 ) 𝑧 )  ∈  {  0  } ) ) | 
						
							| 33 | 5 8 31 32 | syl3anbrc | ⊢ ( 𝑅  ∈  Rng  →  {  0  }  ∈  𝑈 ) |