| Step | Hyp | Ref | Expression | 
						
							| 1 |  | df-refld |  |-  RRfld = ( CCfld |`s RR ) | 
						
							| 2 | 1 | oveq1i |  |-  ( RRfld |`s NN0 ) = ( ( CCfld |`s RR ) |`s NN0 ) | 
						
							| 3 |  | reex |  |-  RR e. _V | 
						
							| 4 |  | nn0ssre |  |-  NN0 C_ RR | 
						
							| 5 |  | ressabs |  |-  ( ( RR e. _V /\ NN0 C_ RR ) -> ( ( CCfld |`s RR ) |`s NN0 ) = ( CCfld |`s NN0 ) ) | 
						
							| 6 | 3 4 5 | mp2an |  |-  ( ( CCfld |`s RR ) |`s NN0 ) = ( CCfld |`s NN0 ) | 
						
							| 7 | 2 6 | eqtri |  |-  ( RRfld |`s NN0 ) = ( CCfld |`s NN0 ) | 
						
							| 8 |  | reofld |  |-  RRfld e. oField | 
						
							| 9 |  | isofld |  |-  ( RRfld e. oField <-> ( RRfld e. Field /\ RRfld e. oRing ) ) | 
						
							| 10 | 9 | simprbi |  |-  ( RRfld e. oField -> RRfld e. oRing ) | 
						
							| 11 |  | orngogrp |  |-  ( RRfld e. oRing -> RRfld e. oGrp ) | 
						
							| 12 |  | isogrp |  |-  ( RRfld e. oGrp <-> ( RRfld e. Grp /\ RRfld e. oMnd ) ) | 
						
							| 13 | 12 | simprbi |  |-  ( RRfld e. oGrp -> RRfld e. oMnd ) | 
						
							| 14 | 10 11 13 | 3syl |  |-  ( RRfld e. oField -> RRfld e. oMnd ) | 
						
							| 15 | 8 14 | ax-mp |  |-  RRfld e. oMnd | 
						
							| 16 |  | nn0subm |  |-  NN0 e. ( SubMnd ` CCfld ) | 
						
							| 17 |  | eqid |  |-  ( CCfld |`s NN0 ) = ( CCfld |`s NN0 ) | 
						
							| 18 | 17 | submmnd |  |-  ( NN0 e. ( SubMnd ` CCfld ) -> ( CCfld |`s NN0 ) e. Mnd ) | 
						
							| 19 | 16 18 | ax-mp |  |-  ( CCfld |`s NN0 ) e. Mnd | 
						
							| 20 | 7 19 | eqeltri |  |-  ( RRfld |`s NN0 ) e. Mnd | 
						
							| 21 |  | submomnd |  |-  ( ( RRfld e. oMnd /\ ( RRfld |`s NN0 ) e. Mnd ) -> ( RRfld |`s NN0 ) e. oMnd ) | 
						
							| 22 | 15 20 21 | mp2an |  |-  ( RRfld |`s NN0 ) e. oMnd | 
						
							| 23 | 7 22 | eqeltrri |  |-  ( CCfld |`s NN0 ) e. oMnd |