| Step | Hyp | Ref | Expression | 
						
							| 1 |  | resscdrg.1 | ⊢ 𝐹  =  ( ℂfld  ↾s  𝐾 ) | 
						
							| 2 |  | eqid | ⊢ ( TopOpen ‘ ℂfld )  =  ( TopOpen ‘ ℂfld ) | 
						
							| 3 | 2 | cnfldtop | ⊢ ( TopOpen ‘ ℂfld )  ∈  Top | 
						
							| 4 |  | ax-resscn | ⊢ ℝ  ⊆  ℂ | 
						
							| 5 |  | qssre | ⊢ ℚ  ⊆  ℝ | 
						
							| 6 |  | unicntop | ⊢ ℂ  =  ∪  ( TopOpen ‘ ℂfld ) | 
						
							| 7 |  | tgioo4 | ⊢ ( topGen ‘ ran  (,) )  =  ( ( TopOpen ‘ ℂfld )  ↾t  ℝ ) | 
						
							| 8 | 6 7 | restcls | ⊢ ( ( ( TopOpen ‘ ℂfld )  ∈  Top  ∧  ℝ  ⊆  ℂ  ∧  ℚ  ⊆  ℝ )  →  ( ( cls ‘ ( topGen ‘ ran  (,) ) ) ‘ ℚ )  =  ( ( ( cls ‘ ( TopOpen ‘ ℂfld ) ) ‘ ℚ )  ∩  ℝ ) ) | 
						
							| 9 | 3 4 5 8 | mp3an | ⊢ ( ( cls ‘ ( topGen ‘ ran  (,) ) ) ‘ ℚ )  =  ( ( ( cls ‘ ( TopOpen ‘ ℂfld ) ) ‘ ℚ )  ∩  ℝ ) | 
						
							| 10 |  | qdensere | ⊢ ( ( cls ‘ ( topGen ‘ ran  (,) ) ) ‘ ℚ )  =  ℝ | 
						
							| 11 | 9 10 | eqtr3i | ⊢ ( ( ( cls ‘ ( TopOpen ‘ ℂfld ) ) ‘ ℚ )  ∩  ℝ )  =  ℝ | 
						
							| 12 |  | sseqin2 | ⊢ ( ℝ  ⊆  ( ( cls ‘ ( TopOpen ‘ ℂfld ) ) ‘ ℚ )  ↔  ( ( ( cls ‘ ( TopOpen ‘ ℂfld ) ) ‘ ℚ )  ∩  ℝ )  =  ℝ ) | 
						
							| 13 | 11 12 | mpbir | ⊢ ℝ  ⊆  ( ( cls ‘ ( TopOpen ‘ ℂfld ) ) ‘ ℚ ) | 
						
							| 14 |  | simp3 | ⊢ ( ( 𝐾  ∈  ( SubRing ‘ ℂfld )  ∧  𝐹  ∈  DivRing  ∧  𝐹  ∈  CMetSp )  →  𝐹  ∈  CMetSp ) | 
						
							| 15 |  | cncms | ⊢ ℂfld  ∈  CMetSp | 
						
							| 16 |  | cnfldbas | ⊢ ℂ  =  ( Base ‘ ℂfld ) | 
						
							| 17 | 16 | subrgss | ⊢ ( 𝐾  ∈  ( SubRing ‘ ℂfld )  →  𝐾  ⊆  ℂ ) | 
						
							| 18 | 17 | 3ad2ant1 | ⊢ ( ( 𝐾  ∈  ( SubRing ‘ ℂfld )  ∧  𝐹  ∈  DivRing  ∧  𝐹  ∈  CMetSp )  →  𝐾  ⊆  ℂ ) | 
						
							| 19 | 1 16 2 | cmsss | ⊢ ( ( ℂfld  ∈  CMetSp  ∧  𝐾  ⊆  ℂ )  →  ( 𝐹  ∈  CMetSp  ↔  𝐾  ∈  ( Clsd ‘ ( TopOpen ‘ ℂfld ) ) ) ) | 
						
							| 20 | 15 18 19 | sylancr | ⊢ ( ( 𝐾  ∈  ( SubRing ‘ ℂfld )  ∧  𝐹  ∈  DivRing  ∧  𝐹  ∈  CMetSp )  →  ( 𝐹  ∈  CMetSp  ↔  𝐾  ∈  ( Clsd ‘ ( TopOpen ‘ ℂfld ) ) ) ) | 
						
							| 21 | 14 20 | mpbid | ⊢ ( ( 𝐾  ∈  ( SubRing ‘ ℂfld )  ∧  𝐹  ∈  DivRing  ∧  𝐹  ∈  CMetSp )  →  𝐾  ∈  ( Clsd ‘ ( TopOpen ‘ ℂfld ) ) ) | 
						
							| 22 | 1 | eleq1i | ⊢ ( 𝐹  ∈  DivRing  ↔  ( ℂfld  ↾s  𝐾 )  ∈  DivRing ) | 
						
							| 23 |  | qsssubdrg | ⊢ ( ( 𝐾  ∈  ( SubRing ‘ ℂfld )  ∧  ( ℂfld  ↾s  𝐾 )  ∈  DivRing )  →  ℚ  ⊆  𝐾 ) | 
						
							| 24 | 22 23 | sylan2b | ⊢ ( ( 𝐾  ∈  ( SubRing ‘ ℂfld )  ∧  𝐹  ∈  DivRing )  →  ℚ  ⊆  𝐾 ) | 
						
							| 25 | 24 | 3adant3 | ⊢ ( ( 𝐾  ∈  ( SubRing ‘ ℂfld )  ∧  𝐹  ∈  DivRing  ∧  𝐹  ∈  CMetSp )  →  ℚ  ⊆  𝐾 ) | 
						
							| 26 | 6 | clsss2 | ⊢ ( ( 𝐾  ∈  ( Clsd ‘ ( TopOpen ‘ ℂfld ) )  ∧  ℚ  ⊆  𝐾 )  →  ( ( cls ‘ ( TopOpen ‘ ℂfld ) ) ‘ ℚ )  ⊆  𝐾 ) | 
						
							| 27 | 21 25 26 | syl2anc | ⊢ ( ( 𝐾  ∈  ( SubRing ‘ ℂfld )  ∧  𝐹  ∈  DivRing  ∧  𝐹  ∈  CMetSp )  →  ( ( cls ‘ ( TopOpen ‘ ℂfld ) ) ‘ ℚ )  ⊆  𝐾 ) | 
						
							| 28 | 13 27 | sstrid | ⊢ ( ( 𝐾  ∈  ( SubRing ‘ ℂfld )  ∧  𝐹  ∈  DivRing  ∧  𝐹  ∈  CMetSp )  →  ℝ  ⊆  𝐾 ) |