| Step | Hyp | Ref | Expression | 
						
							| 1 |  | cnnrg | ⊢ ℂfld  ∈  NrmRing | 
						
							| 2 |  | resubdrg | ⊢ ( ℝ  ∈  ( SubRing ‘ ℂfld )  ∧  ℝfld  ∈  DivRing ) | 
						
							| 3 | 2 | simpli | ⊢ ℝ  ∈  ( SubRing ‘ ℂfld ) | 
						
							| 4 |  | df-refld | ⊢ ℝfld  =  ( ℂfld  ↾s  ℝ ) | 
						
							| 5 | 4 | subrgnrg | ⊢ ( ( ℂfld  ∈  NrmRing  ∧  ℝ  ∈  ( SubRing ‘ ℂfld ) )  →  ℝfld  ∈  NrmRing ) | 
						
							| 6 | 1 3 5 | mp2an | ⊢ ℝfld  ∈  NrmRing | 
						
							| 7 | 2 | simpri | ⊢ ℝfld  ∈  DivRing | 
						
							| 8 | 6 7 | pm3.2i | ⊢ ( ℝfld  ∈  NrmRing  ∧  ℝfld  ∈  DivRing ) | 
						
							| 9 |  | rezh | ⊢ ( ℤMod ‘ ℝfld )  ∈  NrmMod | 
						
							| 10 |  | reofld | ⊢ ℝfld  ∈  oField | 
						
							| 11 |  | ofldchr | ⊢ ( ℝfld  ∈  oField  →  ( chr ‘ ℝfld )  =  0 ) | 
						
							| 12 | 10 11 | ax-mp | ⊢ ( chr ‘ ℝfld )  =  0 | 
						
							| 13 | 9 12 | pm3.2i | ⊢ ( ( ℤMod ‘ ℝfld )  ∈  NrmMod  ∧  ( chr ‘ ℝfld )  =  0 ) | 
						
							| 14 |  | recusp | ⊢ ℝfld  ∈  CUnifSp | 
						
							| 15 |  | reust | ⊢ ( UnifSt ‘ ℝfld )  =  ( metUnif ‘ ( ( dist ‘ ℝfld )  ↾  ( ℝ  ×  ℝ ) ) ) | 
						
							| 16 | 14 15 | pm3.2i | ⊢ ( ℝfld  ∈  CUnifSp  ∧  ( UnifSt ‘ ℝfld )  =  ( metUnif ‘ ( ( dist ‘ ℝfld )  ↾  ( ℝ  ×  ℝ ) ) ) ) | 
						
							| 17 |  | rebase | ⊢ ℝ  =  ( Base ‘ ℝfld ) | 
						
							| 18 |  | eqid | ⊢ ( ( dist ‘ ℝfld )  ↾  ( ℝ  ×  ℝ ) )  =  ( ( dist ‘ ℝfld )  ↾  ( ℝ  ×  ℝ ) ) | 
						
							| 19 |  | eqid | ⊢ ( ℤMod ‘ ℝfld )  =  ( ℤMod ‘ ℝfld ) | 
						
							| 20 | 17 18 19 | isrrext | ⊢ ( ℝfld  ∈   ℝExt   ↔  ( ( ℝfld  ∈  NrmRing  ∧  ℝfld  ∈  DivRing )  ∧  ( ( ℤMod ‘ ℝfld )  ∈  NrmMod  ∧  ( chr ‘ ℝfld )  =  0 )  ∧  ( ℝfld  ∈  CUnifSp  ∧  ( UnifSt ‘ ℝfld )  =  ( metUnif ‘ ( ( dist ‘ ℝfld )  ↾  ( ℝ  ×  ℝ ) ) ) ) ) ) | 
						
							| 21 | 8 13 16 20 | mpbir3an | ⊢ ℝfld  ∈   ℝExt |