| Step | Hyp | Ref | Expression | 
						
							| 1 |  | uznzr.1 | ⊢ 𝐺  =  ( 1st  ‘ 𝑅 ) | 
						
							| 2 |  | uznzr.2 | ⊢ 𝐻  =  ( 2nd  ‘ 𝑅 ) | 
						
							| 3 |  | uznzr.3 | ⊢ 𝑍  =  ( GId ‘ 𝐺 ) | 
						
							| 4 |  | uznzr.4 | ⊢ 𝑈  =  ( GId ‘ 𝐻 ) | 
						
							| 5 |  | uznzr.5 | ⊢ 𝑋  =  ran  𝐺 | 
						
							| 6 | 1 5 3 | rngo0cl | ⊢ ( 𝑅  ∈  RingOps  →  𝑍  ∈  𝑋 ) | 
						
							| 7 |  | en1eqsn | ⊢ ( ( 𝑍  ∈  𝑋  ∧  𝑋  ≈  1o )  →  𝑋  =  { 𝑍 } ) | 
						
							| 8 | 1 | rneqi | ⊢ ran  𝐺  =  ran  ( 1st  ‘ 𝑅 ) | 
						
							| 9 | 8 2 4 | rngo1cl | ⊢ ( 𝑅  ∈  RingOps  →  𝑈  ∈  ran  𝐺 ) | 
						
							| 10 |  | eleq2 | ⊢ ( 𝑋  =  { 𝑍 }  →  ( 𝑈  ∈  𝑋  ↔  𝑈  ∈  { 𝑍 } ) ) | 
						
							| 11 | 10 | biimpd | ⊢ ( 𝑋  =  { 𝑍 }  →  ( 𝑈  ∈  𝑋  →  𝑈  ∈  { 𝑍 } ) ) | 
						
							| 12 |  | elsni | ⊢ ( 𝑈  ∈  { 𝑍 }  →  𝑈  =  𝑍 ) | 
						
							| 13 | 11 12 | syl6com | ⊢ ( 𝑈  ∈  𝑋  →  ( 𝑋  =  { 𝑍 }  →  𝑈  =  𝑍 ) ) | 
						
							| 14 | 5 | eqcomi | ⊢ ran  𝐺  =  𝑋 | 
						
							| 15 | 13 14 | eleq2s | ⊢ ( 𝑈  ∈  ran  𝐺  →  ( 𝑋  =  { 𝑍 }  →  𝑈  =  𝑍 ) ) | 
						
							| 16 | 9 15 | syl | ⊢ ( 𝑅  ∈  RingOps  →  ( 𝑋  =  { 𝑍 }  →  𝑈  =  𝑍 ) ) | 
						
							| 17 | 7 16 | syl5com | ⊢ ( ( 𝑍  ∈  𝑋  ∧  𝑋  ≈  1o )  →  ( 𝑅  ∈  RingOps  →  𝑈  =  𝑍 ) ) | 
						
							| 18 | 17 | ex | ⊢ ( 𝑍  ∈  𝑋  →  ( 𝑋  ≈  1o  →  ( 𝑅  ∈  RingOps  →  𝑈  =  𝑍 ) ) ) | 
						
							| 19 | 18 | com23 | ⊢ ( 𝑍  ∈  𝑋  →  ( 𝑅  ∈  RingOps  →  ( 𝑋  ≈  1o  →  𝑈  =  𝑍 ) ) ) | 
						
							| 20 | 6 19 | mpcom | ⊢ ( 𝑅  ∈  RingOps  →  ( 𝑋  ≈  1o  →  𝑈  =  𝑍 ) ) | 
						
							| 21 | 1 5 | rngone0 | ⊢ ( 𝑅  ∈  RingOps  →  𝑋  ≠  ∅ ) | 
						
							| 22 |  | oveq2 | ⊢ ( 𝑈  =  𝑍  →  ( 𝑥 𝐻 𝑈 )  =  ( 𝑥 𝐻 𝑍 ) ) | 
						
							| 23 | 22 | ralrimivw | ⊢ ( 𝑈  =  𝑍  →  ∀ 𝑥  ∈  𝑋 ( 𝑥 𝐻 𝑈 )  =  ( 𝑥 𝐻 𝑍 ) ) | 
						
							| 24 | 3 5 1 2 | rngorz | ⊢ ( ( 𝑅  ∈  RingOps  ∧  𝑥  ∈  𝑋 )  →  ( 𝑥 𝐻 𝑍 )  =  𝑍 ) | 
						
							| 25 | 24 | ralrimiva | ⊢ ( 𝑅  ∈  RingOps  →  ∀ 𝑥  ∈  𝑋 ( 𝑥 𝐻 𝑍 )  =  𝑍 ) | 
						
							| 26 | 5 8 | eqtri | ⊢ 𝑋  =  ran  ( 1st  ‘ 𝑅 ) | 
						
							| 27 | 2 26 4 | rngoridm | ⊢ ( ( 𝑅  ∈  RingOps  ∧  𝑥  ∈  𝑋 )  →  ( 𝑥 𝐻 𝑈 )  =  𝑥 ) | 
						
							| 28 | 27 | ralrimiva | ⊢ ( 𝑅  ∈  RingOps  →  ∀ 𝑥  ∈  𝑋 ( 𝑥 𝐻 𝑈 )  =  𝑥 ) | 
						
							| 29 |  | r19.26 | ⊢ ( ∀ 𝑥  ∈  𝑋 ( ( 𝑥 𝐻 𝑈 )  =  𝑥  ∧  ( 𝑥 𝐻 𝑈 )  =  ( 𝑥 𝐻 𝑍 ) )  ↔  ( ∀ 𝑥  ∈  𝑋 ( 𝑥 𝐻 𝑈 )  =  𝑥  ∧  ∀ 𝑥  ∈  𝑋 ( 𝑥 𝐻 𝑈 )  =  ( 𝑥 𝐻 𝑍 ) ) ) | 
						
							| 30 |  | r19.26 | ⊢ ( ∀ 𝑥  ∈  𝑋 ( ( ( 𝑥 𝐻 𝑈 )  =  𝑥  ∧  ( 𝑥 𝐻 𝑈 )  =  ( 𝑥 𝐻 𝑍 ) )  ∧  ( 𝑥 𝐻 𝑍 )  =  𝑍 )  ↔  ( ∀ 𝑥  ∈  𝑋 ( ( 𝑥 𝐻 𝑈 )  =  𝑥  ∧  ( 𝑥 𝐻 𝑈 )  =  ( 𝑥 𝐻 𝑍 ) )  ∧  ∀ 𝑥  ∈  𝑋 ( 𝑥 𝐻 𝑍 )  =  𝑍 ) ) | 
						
							| 31 |  | eqtr | ⊢ ( ( 𝑥  =  ( 𝑥 𝐻 𝑈 )  ∧  ( 𝑥 𝐻 𝑈 )  =  ( 𝑥 𝐻 𝑍 ) )  →  𝑥  =  ( 𝑥 𝐻 𝑍 ) ) | 
						
							| 32 |  | eqtr | ⊢ ( ( 𝑥  =  ( 𝑥 𝐻 𝑍 )  ∧  ( 𝑥 𝐻 𝑍 )  =  𝑍 )  →  𝑥  =  𝑍 ) | 
						
							| 33 | 32 | ex | ⊢ ( 𝑥  =  ( 𝑥 𝐻 𝑍 )  →  ( ( 𝑥 𝐻 𝑍 )  =  𝑍  →  𝑥  =  𝑍 ) ) | 
						
							| 34 | 31 33 | syl | ⊢ ( ( 𝑥  =  ( 𝑥 𝐻 𝑈 )  ∧  ( 𝑥 𝐻 𝑈 )  =  ( 𝑥 𝐻 𝑍 ) )  →  ( ( 𝑥 𝐻 𝑍 )  =  𝑍  →  𝑥  =  𝑍 ) ) | 
						
							| 35 | 34 | ex | ⊢ ( 𝑥  =  ( 𝑥 𝐻 𝑈 )  →  ( ( 𝑥 𝐻 𝑈 )  =  ( 𝑥 𝐻 𝑍 )  →  ( ( 𝑥 𝐻 𝑍 )  =  𝑍  →  𝑥  =  𝑍 ) ) ) | 
						
							| 36 | 35 | eqcoms | ⊢ ( ( 𝑥 𝐻 𝑈 )  =  𝑥  →  ( ( 𝑥 𝐻 𝑈 )  =  ( 𝑥 𝐻 𝑍 )  →  ( ( 𝑥 𝐻 𝑍 )  =  𝑍  →  𝑥  =  𝑍 ) ) ) | 
						
							| 37 | 36 | imp31 | ⊢ ( ( ( ( 𝑥 𝐻 𝑈 )  =  𝑥  ∧  ( 𝑥 𝐻 𝑈 )  =  ( 𝑥 𝐻 𝑍 ) )  ∧  ( 𝑥 𝐻 𝑍 )  =  𝑍 )  →  𝑥  =  𝑍 ) | 
						
							| 38 | 37 | ralimi | ⊢ ( ∀ 𝑥  ∈  𝑋 ( ( ( 𝑥 𝐻 𝑈 )  =  𝑥  ∧  ( 𝑥 𝐻 𝑈 )  =  ( 𝑥 𝐻 𝑍 ) )  ∧  ( 𝑥 𝐻 𝑍 )  =  𝑍 )  →  ∀ 𝑥  ∈  𝑋 𝑥  =  𝑍 ) | 
						
							| 39 |  | eqsn | ⊢ ( 𝑋  ≠  ∅  →  ( 𝑋  =  { 𝑍 }  ↔  ∀ 𝑥  ∈  𝑋 𝑥  =  𝑍 ) ) | 
						
							| 40 |  | ensn1g | ⊢ ( 𝑍  ∈  𝑋  →  { 𝑍 }  ≈  1o ) | 
						
							| 41 | 6 40 | syl | ⊢ ( 𝑅  ∈  RingOps  →  { 𝑍 }  ≈  1o ) | 
						
							| 42 |  | breq1 | ⊢ ( 𝑋  =  { 𝑍 }  →  ( 𝑋  ≈  1o  ↔  { 𝑍 }  ≈  1o ) ) | 
						
							| 43 | 41 42 | imbitrrid | ⊢ ( 𝑋  =  { 𝑍 }  →  ( 𝑅  ∈  RingOps  →  𝑋  ≈  1o ) ) | 
						
							| 44 | 39 43 | biimtrrdi | ⊢ ( 𝑋  ≠  ∅  →  ( ∀ 𝑥  ∈  𝑋 𝑥  =  𝑍  →  ( 𝑅  ∈  RingOps  →  𝑋  ≈  1o ) ) ) | 
						
							| 45 | 44 | com3l | ⊢ ( ∀ 𝑥  ∈  𝑋 𝑥  =  𝑍  →  ( 𝑅  ∈  RingOps  →  ( 𝑋  ≠  ∅  →  𝑋  ≈  1o ) ) ) | 
						
							| 46 | 38 45 | syl | ⊢ ( ∀ 𝑥  ∈  𝑋 ( ( ( 𝑥 𝐻 𝑈 )  =  𝑥  ∧  ( 𝑥 𝐻 𝑈 )  =  ( 𝑥 𝐻 𝑍 ) )  ∧  ( 𝑥 𝐻 𝑍 )  =  𝑍 )  →  ( 𝑅  ∈  RingOps  →  ( 𝑋  ≠  ∅  →  𝑋  ≈  1o ) ) ) | 
						
							| 47 | 30 46 | sylbir | ⊢ ( ( ∀ 𝑥  ∈  𝑋 ( ( 𝑥 𝐻 𝑈 )  =  𝑥  ∧  ( 𝑥 𝐻 𝑈 )  =  ( 𝑥 𝐻 𝑍 ) )  ∧  ∀ 𝑥  ∈  𝑋 ( 𝑥 𝐻 𝑍 )  =  𝑍 )  →  ( 𝑅  ∈  RingOps  →  ( 𝑋  ≠  ∅  →  𝑋  ≈  1o ) ) ) | 
						
							| 48 | 47 | ex | ⊢ ( ∀ 𝑥  ∈  𝑋 ( ( 𝑥 𝐻 𝑈 )  =  𝑥  ∧  ( 𝑥 𝐻 𝑈 )  =  ( 𝑥 𝐻 𝑍 ) )  →  ( ∀ 𝑥  ∈  𝑋 ( 𝑥 𝐻 𝑍 )  =  𝑍  →  ( 𝑅  ∈  RingOps  →  ( 𝑋  ≠  ∅  →  𝑋  ≈  1o ) ) ) ) | 
						
							| 49 | 29 48 | sylbir | ⊢ ( ( ∀ 𝑥  ∈  𝑋 ( 𝑥 𝐻 𝑈 )  =  𝑥  ∧  ∀ 𝑥  ∈  𝑋 ( 𝑥 𝐻 𝑈 )  =  ( 𝑥 𝐻 𝑍 ) )  →  ( ∀ 𝑥  ∈  𝑋 ( 𝑥 𝐻 𝑍 )  =  𝑍  →  ( 𝑅  ∈  RingOps  →  ( 𝑋  ≠  ∅  →  𝑋  ≈  1o ) ) ) ) | 
						
							| 50 | 49 | ex | ⊢ ( ∀ 𝑥  ∈  𝑋 ( 𝑥 𝐻 𝑈 )  =  𝑥  →  ( ∀ 𝑥  ∈  𝑋 ( 𝑥 𝐻 𝑈 )  =  ( 𝑥 𝐻 𝑍 )  →  ( ∀ 𝑥  ∈  𝑋 ( 𝑥 𝐻 𝑍 )  =  𝑍  →  ( 𝑅  ∈  RingOps  →  ( 𝑋  ≠  ∅  →  𝑋  ≈  1o ) ) ) ) ) | 
						
							| 51 | 50 | com24 | ⊢ ( ∀ 𝑥  ∈  𝑋 ( 𝑥 𝐻 𝑈 )  =  𝑥  →  ( 𝑅  ∈  RingOps  →  ( ∀ 𝑥  ∈  𝑋 ( 𝑥 𝐻 𝑍 )  =  𝑍  →  ( ∀ 𝑥  ∈  𝑋 ( 𝑥 𝐻 𝑈 )  =  ( 𝑥 𝐻 𝑍 )  →  ( 𝑋  ≠  ∅  →  𝑋  ≈  1o ) ) ) ) ) | 
						
							| 52 | 28 51 | mpcom | ⊢ ( 𝑅  ∈  RingOps  →  ( ∀ 𝑥  ∈  𝑋 ( 𝑥 𝐻 𝑍 )  =  𝑍  →  ( ∀ 𝑥  ∈  𝑋 ( 𝑥 𝐻 𝑈 )  =  ( 𝑥 𝐻 𝑍 )  →  ( 𝑋  ≠  ∅  →  𝑋  ≈  1o ) ) ) ) | 
						
							| 53 | 25 52 | mpd | ⊢ ( 𝑅  ∈  RingOps  →  ( ∀ 𝑥  ∈  𝑋 ( 𝑥 𝐻 𝑈 )  =  ( 𝑥 𝐻 𝑍 )  →  ( 𝑋  ≠  ∅  →  𝑋  ≈  1o ) ) ) | 
						
							| 54 | 23 53 | syl5com | ⊢ ( 𝑈  =  𝑍  →  ( 𝑅  ∈  RingOps  →  ( 𝑋  ≠  ∅  →  𝑋  ≈  1o ) ) ) | 
						
							| 55 | 54 | com13 | ⊢ ( 𝑋  ≠  ∅  →  ( 𝑅  ∈  RingOps  →  ( 𝑈  =  𝑍  →  𝑋  ≈  1o ) ) ) | 
						
							| 56 | 21 55 | mpcom | ⊢ ( 𝑅  ∈  RingOps  →  ( 𝑈  =  𝑍  →  𝑋  ≈  1o ) ) | 
						
							| 57 | 20 56 | impbid | ⊢ ( 𝑅  ∈  RingOps  →  ( 𝑋  ≈  1o  ↔  𝑈  =  𝑍 ) ) |