| Step | Hyp | Ref | Expression | 
						
							| 1 |  | cycpmconjvlem.f |  |-  ( ph -> F : D -1-1-onto-> D ) | 
						
							| 2 |  | cycpmconjvlem.b |  |-  ( ph -> B C_ D ) | 
						
							| 3 |  | f1ofun |  |-  ( F : D -1-1-onto-> D -> Fun F ) | 
						
							| 4 | 1 3 | syl |  |-  ( ph -> Fun F ) | 
						
							| 5 |  | funrel |  |-  ( Fun F -> Rel F ) | 
						
							| 6 |  | dfrel2 |  |-  ( Rel F <-> `' `' F = F ) | 
						
							| 7 | 5 6 | sylib |  |-  ( Fun F -> `' `' F = F ) | 
						
							| 8 | 7 | reseq1d |  |-  ( Fun F -> ( `' `' F |` ( D \ B ) ) = ( F |` ( D \ B ) ) ) | 
						
							| 9 | 8 | cnveqd |  |-  ( Fun F -> `' ( `' `' F |` ( D \ B ) ) = `' ( F |` ( D \ B ) ) ) | 
						
							| 10 | 9 | coeq2d |  |-  ( Fun F -> ( ( F |` ( D \ B ) ) o. `' ( `' `' F |` ( D \ B ) ) ) = ( ( F |` ( D \ B ) ) o. `' ( F |` ( D \ B ) ) ) ) | 
						
							| 11 | 4 10 | syl |  |-  ( ph -> ( ( F |` ( D \ B ) ) o. `' ( `' `' F |` ( D \ B ) ) ) = ( ( F |` ( D \ B ) ) o. `' ( F |` ( D \ B ) ) ) ) | 
						
							| 12 |  | difssd |  |-  ( ph -> ( D \ B ) C_ D ) | 
						
							| 13 |  | f1odm |  |-  ( F : D -1-1-onto-> D -> dom F = D ) | 
						
							| 14 | 1 13 | syl |  |-  ( ph -> dom F = D ) | 
						
							| 15 | 12 14 | sseqtrrd |  |-  ( ph -> ( D \ B ) C_ dom F ) | 
						
							| 16 |  | ssdmres |  |-  ( ( D \ B ) C_ dom F <-> dom ( F |` ( D \ B ) ) = ( D \ B ) ) | 
						
							| 17 | 15 16 | sylib |  |-  ( ph -> dom ( F |` ( D \ B ) ) = ( D \ B ) ) | 
						
							| 18 |  | ssidd |  |-  ( ph -> ( D \ B ) C_ ( D \ B ) ) | 
						
							| 19 | 17 18 | eqsstrd |  |-  ( ph -> dom ( F |` ( D \ B ) ) C_ ( D \ B ) ) | 
						
							| 20 |  | cores2 |  |-  ( dom ( F |` ( D \ B ) ) C_ ( D \ B ) -> ( ( F |` ( D \ B ) ) o. `' ( `' `' F |` ( D \ B ) ) ) = ( ( F |` ( D \ B ) ) o. `' F ) ) | 
						
							| 21 | 19 20 | syl |  |-  ( ph -> ( ( F |` ( D \ B ) ) o. `' ( `' `' F |` ( D \ B ) ) ) = ( ( F |` ( D \ B ) ) o. `' F ) ) | 
						
							| 22 |  | f1ocnv |  |-  ( F : D -1-1-onto-> D -> `' F : D -1-1-onto-> D ) | 
						
							| 23 |  | f1ofun |  |-  ( `' F : D -1-1-onto-> D -> Fun `' F ) | 
						
							| 24 | 1 22 23 | 3syl |  |-  ( ph -> Fun `' F ) | 
						
							| 25 |  | ssidd |  |-  ( ph -> D C_ D ) | 
						
							| 26 | 25 14 | sseqtrrd |  |-  ( ph -> D C_ dom F ) | 
						
							| 27 |  | fores |  |-  ( ( Fun F /\ D C_ dom F ) -> ( F |` D ) : D -onto-> ( F " D ) ) | 
						
							| 28 | 4 26 27 | syl2anc |  |-  ( ph -> ( F |` D ) : D -onto-> ( F " D ) ) | 
						
							| 29 |  | df-ima |  |-  ( F " D ) = ran ( F |` D ) | 
						
							| 30 |  | foeq3 |  |-  ( ( F " D ) = ran ( F |` D ) -> ( ( F |` D ) : D -onto-> ( F " D ) <-> ( F |` D ) : D -onto-> ran ( F |` D ) ) ) | 
						
							| 31 | 29 30 | ax-mp |  |-  ( ( F |` D ) : D -onto-> ( F " D ) <-> ( F |` D ) : D -onto-> ran ( F |` D ) ) | 
						
							| 32 | 28 31 | sylib |  |-  ( ph -> ( F |` D ) : D -onto-> ran ( F |` D ) ) | 
						
							| 33 | 2 14 | sseqtrrd |  |-  ( ph -> B C_ dom F ) | 
						
							| 34 |  | fores |  |-  ( ( Fun F /\ B C_ dom F ) -> ( F |` B ) : B -onto-> ( F " B ) ) | 
						
							| 35 | 4 33 34 | syl2anc |  |-  ( ph -> ( F |` B ) : B -onto-> ( F " B ) ) | 
						
							| 36 |  | df-ima |  |-  ( F " B ) = ran ( F |` B ) | 
						
							| 37 |  | foeq3 |  |-  ( ( F " B ) = ran ( F |` B ) -> ( ( F |` B ) : B -onto-> ( F " B ) <-> ( F |` B ) : B -onto-> ran ( F |` B ) ) ) | 
						
							| 38 | 36 37 | ax-mp |  |-  ( ( F |` B ) : B -onto-> ( F " B ) <-> ( F |` B ) : B -onto-> ran ( F |` B ) ) | 
						
							| 39 | 35 38 | sylib |  |-  ( ph -> ( F |` B ) : B -onto-> ran ( F |` B ) ) | 
						
							| 40 |  | resdif |  |-  ( ( Fun `' F /\ ( F |` D ) : D -onto-> ran ( F |` D ) /\ ( F |` B ) : B -onto-> ran ( F |` B ) ) -> ( F |` ( D \ B ) ) : ( D \ B ) -1-1-onto-> ( ran ( F |` D ) \ ran ( F |` B ) ) ) | 
						
							| 41 | 24 32 39 40 | syl3anc |  |-  ( ph -> ( F |` ( D \ B ) ) : ( D \ B ) -1-1-onto-> ( ran ( F |` D ) \ ran ( F |` B ) ) ) | 
						
							| 42 |  | f1ofn |  |-  ( F : D -1-1-onto-> D -> F Fn D ) | 
						
							| 43 |  | fnresdm |  |-  ( F Fn D -> ( F |` D ) = F ) | 
						
							| 44 | 1 42 43 | 3syl |  |-  ( ph -> ( F |` D ) = F ) | 
						
							| 45 | 44 | rneqd |  |-  ( ph -> ran ( F |` D ) = ran F ) | 
						
							| 46 |  | f1ofo |  |-  ( F : D -1-1-onto-> D -> F : D -onto-> D ) | 
						
							| 47 |  | forn |  |-  ( F : D -onto-> D -> ran F = D ) | 
						
							| 48 | 1 46 47 | 3syl |  |-  ( ph -> ran F = D ) | 
						
							| 49 | 45 48 | eqtrd |  |-  ( ph -> ran ( F |` D ) = D ) | 
						
							| 50 | 49 | difeq1d |  |-  ( ph -> ( ran ( F |` D ) \ ran ( F |` B ) ) = ( D \ ran ( F |` B ) ) ) | 
						
							| 51 | 50 | f1oeq3d |  |-  ( ph -> ( ( F |` ( D \ B ) ) : ( D \ B ) -1-1-onto-> ( ran ( F |` D ) \ ran ( F |` B ) ) <-> ( F |` ( D \ B ) ) : ( D \ B ) -1-1-onto-> ( D \ ran ( F |` B ) ) ) ) | 
						
							| 52 | 41 51 | mpbid |  |-  ( ph -> ( F |` ( D \ B ) ) : ( D \ B ) -1-1-onto-> ( D \ ran ( F |` B ) ) ) | 
						
							| 53 |  | f1ococnv2 |  |-  ( ( F |` ( D \ B ) ) : ( D \ B ) -1-1-onto-> ( D \ ran ( F |` B ) ) -> ( ( F |` ( D \ B ) ) o. `' ( F |` ( D \ B ) ) ) = ( _I |` ( D \ ran ( F |` B ) ) ) ) | 
						
							| 54 | 52 53 | syl |  |-  ( ph -> ( ( F |` ( D \ B ) ) o. `' ( F |` ( D \ B ) ) ) = ( _I |` ( D \ ran ( F |` B ) ) ) ) | 
						
							| 55 | 11 21 54 | 3eqtr3d |  |-  ( ph -> ( ( F |` ( D \ B ) ) o. `' F ) = ( _I |` ( D \ ran ( F |` B ) ) ) ) |