| Step | Hyp | Ref | Expression | 
						
							| 1 |  | rngqiprngfu.r | ⊢ ( 𝜑  →  𝑅  ∈  Rng ) | 
						
							| 2 |  | rngqiprngfu.i | ⊢ ( 𝜑  →  𝐼  ∈  ( 2Ideal ‘ 𝑅 ) ) | 
						
							| 3 |  | rngqiprngfu.j | ⊢ 𝐽  =  ( 𝑅  ↾s  𝐼 ) | 
						
							| 4 |  | rngqiprngfu.u | ⊢ ( 𝜑  →  𝐽  ∈  Ring ) | 
						
							| 5 |  | rngqiprngfu.b | ⊢ 𝐵  =  ( Base ‘ 𝑅 ) | 
						
							| 6 |  | rngqiprngfu.t | ⊢  ·   =  ( .r ‘ 𝑅 ) | 
						
							| 7 |  | rngqiprngfu.1 | ⊢  1   =  ( 1r ‘ 𝐽 ) | 
						
							| 8 |  | rngqiprngfu.g | ⊢  ∼   =  ( 𝑅  ~QG  𝐼 ) | 
						
							| 9 |  | rngqiprngfu.q | ⊢ 𝑄  =  ( 𝑅  /s   ∼  ) | 
						
							| 10 |  | rngqiprngfu.v | ⊢ ( 𝜑  →  𝑄  ∈  Ring ) | 
						
							| 11 |  | rngqiprngfu.e | ⊢ ( 𝜑  →  𝐸  ∈  ( 1r ‘ 𝑄 ) ) | 
						
							| 12 |  | rngqiprngfu.m | ⊢  −   =  ( -g ‘ 𝑅 ) | 
						
							| 13 |  | rngqiprngfu.a | ⊢  +   =  ( +g ‘ 𝑅 ) | 
						
							| 14 |  | rngqiprngfu.n | ⊢ 𝑈  =  ( ( 𝐸  −  (  1   ·  𝐸 ) )  +   1  ) | 
						
							| 15 | 14 | oveq2i | ⊢ ( 𝐸  −  𝑈 )  =  ( 𝐸  −  ( ( 𝐸  −  (  1   ·  𝐸 ) )  +   1  ) ) | 
						
							| 16 | 15 | a1i | ⊢ ( 𝜑  →  ( 𝐸  −  𝑈 )  =  ( 𝐸  −  ( ( 𝐸  −  (  1   ·  𝐸 ) )  +   1  ) ) ) | 
						
							| 17 |  | rngabl | ⊢ ( 𝑅  ∈  Rng  →  𝑅  ∈  Abel ) | 
						
							| 18 | 1 17 | syl | ⊢ ( 𝜑  →  𝑅  ∈  Abel ) | 
						
							| 19 | 1 2 3 4 5 6 7 8 9 10 11 | rngqiprngfulem2 | ⊢ ( 𝜑  →  𝐸  ∈  𝐵 ) | 
						
							| 20 |  | rnggrp | ⊢ ( 𝑅  ∈  Rng  →  𝑅  ∈  Grp ) | 
						
							| 21 | 1 20 | syl | ⊢ ( 𝜑  →  𝑅  ∈  Grp ) | 
						
							| 22 | 1 2 3 4 5 6 7 | rngqiprng1elbas | ⊢ ( 𝜑  →   1   ∈  𝐵 ) | 
						
							| 23 | 5 6 | rngcl | ⊢ ( ( 𝑅  ∈  Rng  ∧   1   ∈  𝐵  ∧  𝐸  ∈  𝐵 )  →  (  1   ·  𝐸 )  ∈  𝐵 ) | 
						
							| 24 | 1 22 19 23 | syl3anc | ⊢ ( 𝜑  →  (  1   ·  𝐸 )  ∈  𝐵 ) | 
						
							| 25 | 5 12 | grpsubcl | ⊢ ( ( 𝑅  ∈  Grp  ∧  𝐸  ∈  𝐵  ∧  (  1   ·  𝐸 )  ∈  𝐵 )  →  ( 𝐸  −  (  1   ·  𝐸 ) )  ∈  𝐵 ) | 
						
							| 26 | 21 19 24 25 | syl3anc | ⊢ ( 𝜑  →  ( 𝐸  −  (  1   ·  𝐸 ) )  ∈  𝐵 ) | 
						
							| 27 | 5 13 12 18 19 26 22 | ablsubsub4 | ⊢ ( 𝜑  →  ( ( 𝐸  −  ( 𝐸  −  (  1   ·  𝐸 ) ) )  −   1  )  =  ( 𝐸  −  ( ( 𝐸  −  (  1   ·  𝐸 ) )  +   1  ) ) ) | 
						
							| 28 | 5 12 18 19 24 | ablnncan | ⊢ ( 𝜑  →  ( 𝐸  −  ( 𝐸  −  (  1   ·  𝐸 ) ) )  =  (  1   ·  𝐸 ) ) | 
						
							| 29 | 28 | oveq1d | ⊢ ( 𝜑  →  ( ( 𝐸  −  ( 𝐸  −  (  1   ·  𝐸 ) ) )  −   1  )  =  ( (  1   ·  𝐸 )  −   1  ) ) | 
						
							| 30 | 16 27 29 | 3eqtr2d | ⊢ ( 𝜑  →  ( 𝐸  −  𝑈 )  =  ( (  1   ·  𝐸 )  −   1  ) ) | 
						
							| 31 |  | ringrng | ⊢ ( 𝐽  ∈  Ring  →  𝐽  ∈  Rng ) | 
						
							| 32 | 4 31 | syl | ⊢ ( 𝜑  →  𝐽  ∈  Rng ) | 
						
							| 33 | 3 32 | eqeltrrid | ⊢ ( 𝜑  →  ( 𝑅  ↾s  𝐼 )  ∈  Rng ) | 
						
							| 34 | 1 2 33 | rng2idlnsg | ⊢ ( 𝜑  →  𝐼  ∈  ( NrmSGrp ‘ 𝑅 ) ) | 
						
							| 35 |  | nsgsubg | ⊢ ( 𝐼  ∈  ( NrmSGrp ‘ 𝑅 )  →  𝐼  ∈  ( SubGrp ‘ 𝑅 ) ) | 
						
							| 36 | 34 35 | syl | ⊢ ( 𝜑  →  𝐼  ∈  ( SubGrp ‘ 𝑅 ) ) | 
						
							| 37 | 1 2 3 4 5 6 7 | rngqiprngghmlem1 | ⊢ ( ( 𝜑  ∧  𝐸  ∈  𝐵 )  →  (  1   ·  𝐸 )  ∈  ( Base ‘ 𝐽 ) ) | 
						
							| 38 | 19 37 | mpdan | ⊢ ( 𝜑  →  (  1   ·  𝐸 )  ∈  ( Base ‘ 𝐽 ) ) | 
						
							| 39 |  | eqid | ⊢ ( Base ‘ 𝐽 )  =  ( Base ‘ 𝐽 ) | 
						
							| 40 | 2 3 39 | 2idlbas | ⊢ ( 𝜑  →  ( Base ‘ 𝐽 )  =  𝐼 ) | 
						
							| 41 | 38 40 | eleqtrd | ⊢ ( 𝜑  →  (  1   ·  𝐸 )  ∈  𝐼 ) | 
						
							| 42 | 39 7 | ringidcl | ⊢ ( 𝐽  ∈  Ring  →   1   ∈  ( Base ‘ 𝐽 ) ) | 
						
							| 43 | 4 42 | syl | ⊢ ( 𝜑  →   1   ∈  ( Base ‘ 𝐽 ) ) | 
						
							| 44 | 43 40 | eleqtrd | ⊢ ( 𝜑  →   1   ∈  𝐼 ) | 
						
							| 45 |  | eqid | ⊢ ( -g ‘ 𝐽 )  =  ( -g ‘ 𝐽 ) | 
						
							| 46 | 12 3 45 | subgsub | ⊢ ( ( 𝐼  ∈  ( SubGrp ‘ 𝑅 )  ∧  (  1   ·  𝐸 )  ∈  𝐼  ∧   1   ∈  𝐼 )  →  ( (  1   ·  𝐸 )  −   1  )  =  ( (  1   ·  𝐸 ) ( -g ‘ 𝐽 )  1  ) ) | 
						
							| 47 | 36 41 44 46 | syl3anc | ⊢ ( 𝜑  →  ( (  1   ·  𝐸 )  −   1  )  =  ( (  1   ·  𝐸 ) ( -g ‘ 𝐽 )  1  ) ) | 
						
							| 48 | 4 | ringgrpd | ⊢ ( 𝜑  →  𝐽  ∈  Grp ) | 
						
							| 49 | 39 45 | grpsubcl | ⊢ ( ( 𝐽  ∈  Grp  ∧  (  1   ·  𝐸 )  ∈  ( Base ‘ 𝐽 )  ∧   1   ∈  ( Base ‘ 𝐽 ) )  →  ( (  1   ·  𝐸 ) ( -g ‘ 𝐽 )  1  )  ∈  ( Base ‘ 𝐽 ) ) | 
						
							| 50 | 48 38 43 49 | syl3anc | ⊢ ( 𝜑  →  ( (  1   ·  𝐸 ) ( -g ‘ 𝐽 )  1  )  ∈  ( Base ‘ 𝐽 ) ) | 
						
							| 51 | 47 50 | eqeltrd | ⊢ ( 𝜑  →  ( (  1   ·  𝐸 )  −   1  )  ∈  ( Base ‘ 𝐽 ) ) | 
						
							| 52 | 51 40 | eleqtrd | ⊢ ( 𝜑  →  ( (  1   ·  𝐸 )  −   1  )  ∈  𝐼 ) | 
						
							| 53 | 30 52 | eqeltrd | ⊢ ( 𝜑  →  ( 𝐸  −  𝑈 )  ∈  𝐼 ) | 
						
							| 54 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 | rngqiprngfulem3 | ⊢ ( 𝜑  →  𝑈  ∈  𝐵 ) | 
						
							| 55 | 5 12 8 | qusecsub | ⊢ ( ( ( 𝑅  ∈  Abel  ∧  𝐼  ∈  ( SubGrp ‘ 𝑅 ) )  ∧  ( 𝑈  ∈  𝐵  ∧  𝐸  ∈  𝐵 ) )  →  ( [ 𝑈 ]  ∼   =  [ 𝐸 ]  ∼   ↔  ( 𝐸  −  𝑈 )  ∈  𝐼 ) ) | 
						
							| 56 | 18 36 54 19 55 | syl22anc | ⊢ ( 𝜑  →  ( [ 𝑈 ]  ∼   =  [ 𝐸 ]  ∼   ↔  ( 𝐸  −  𝑈 )  ∈  𝐼 ) ) | 
						
							| 57 | 53 56 | mpbird | ⊢ ( 𝜑  →  [ 𝑈 ]  ∼   =  [ 𝐸 ]  ∼  ) |