| Step | Hyp | Ref | Expression | 
						
							| 1 |  | fuciso.q |  |-  Q = ( C FuncCat D ) | 
						
							| 2 |  | fuciso.b |  |-  B = ( Base ` C ) | 
						
							| 3 |  | fuciso.n |  |-  N = ( C Nat D ) | 
						
							| 4 |  | fuciso.f |  |-  ( ph -> F e. ( C Func D ) ) | 
						
							| 5 |  | fuciso.g |  |-  ( ph -> G e. ( C Func D ) ) | 
						
							| 6 |  | fucinv.i |  |-  I = ( Inv ` Q ) | 
						
							| 7 |  | fucinv.j |  |-  J = ( Inv ` D ) | 
						
							| 8 |  | eqid |  |-  ( Sect ` Q ) = ( Sect ` Q ) | 
						
							| 9 |  | eqid |  |-  ( Sect ` D ) = ( Sect ` D ) | 
						
							| 10 | 1 2 3 4 5 8 9 | fucsect |  |-  ( ph -> ( U ( F ( Sect ` Q ) G ) V <-> ( U e. ( F N G ) /\ V e. ( G N F ) /\ A. x e. B ( U ` x ) ( ( ( 1st ` F ) ` x ) ( Sect ` D ) ( ( 1st ` G ) ` x ) ) ( V ` x ) ) ) ) | 
						
							| 11 | 1 2 3 5 4 8 9 | fucsect |  |-  ( ph -> ( V ( G ( Sect ` Q ) F ) U <-> ( V e. ( G N F ) /\ U e. ( F N G ) /\ A. x e. B ( V ` x ) ( ( ( 1st ` G ) ` x ) ( Sect ` D ) ( ( 1st ` F ) ` x ) ) ( U ` x ) ) ) ) | 
						
							| 12 | 10 11 | anbi12d |  |-  ( ph -> ( ( U ( F ( Sect ` Q ) G ) V /\ V ( G ( Sect ` Q ) F ) U ) <-> ( ( U e. ( F N G ) /\ V e. ( G N F ) /\ A. x e. B ( U ` x ) ( ( ( 1st ` F ) ` x ) ( Sect ` D ) ( ( 1st ` G ) ` x ) ) ( V ` x ) ) /\ ( V e. ( G N F ) /\ U e. ( F N G ) /\ A. x e. B ( V ` x ) ( ( ( 1st ` G ) ` x ) ( Sect ` D ) ( ( 1st ` F ) ` x ) ) ( U ` x ) ) ) ) ) | 
						
							| 13 | 1 | fucbas |  |-  ( C Func D ) = ( Base ` Q ) | 
						
							| 14 |  | funcrcl |  |-  ( F e. ( C Func D ) -> ( C e. Cat /\ D e. Cat ) ) | 
						
							| 15 | 4 14 | syl |  |-  ( ph -> ( C e. Cat /\ D e. Cat ) ) | 
						
							| 16 | 15 | simpld |  |-  ( ph -> C e. Cat ) | 
						
							| 17 | 15 | simprd |  |-  ( ph -> D e. Cat ) | 
						
							| 18 | 1 16 17 | fuccat |  |-  ( ph -> Q e. Cat ) | 
						
							| 19 | 13 6 18 4 5 8 | isinv |  |-  ( ph -> ( U ( F I G ) V <-> ( U ( F ( Sect ` Q ) G ) V /\ V ( G ( Sect ` Q ) F ) U ) ) ) | 
						
							| 20 |  | eqid |  |-  ( Base ` D ) = ( Base ` D ) | 
						
							| 21 | 17 | adantr |  |-  ( ( ph /\ x e. B ) -> D e. Cat ) | 
						
							| 22 |  | relfunc |  |-  Rel ( C Func D ) | 
						
							| 23 |  | 1st2ndbr |  |-  ( ( Rel ( C Func D ) /\ F e. ( C Func D ) ) -> ( 1st ` F ) ( C Func D ) ( 2nd ` F ) ) | 
						
							| 24 | 22 4 23 | sylancr |  |-  ( ph -> ( 1st ` F ) ( C Func D ) ( 2nd ` F ) ) | 
						
							| 25 | 2 20 24 | funcf1 |  |-  ( ph -> ( 1st ` F ) : B --> ( Base ` D ) ) | 
						
							| 26 | 25 | ffvelcdmda |  |-  ( ( ph /\ x e. B ) -> ( ( 1st ` F ) ` x ) e. ( Base ` D ) ) | 
						
							| 27 |  | 1st2ndbr |  |-  ( ( Rel ( C Func D ) /\ G e. ( C Func D ) ) -> ( 1st ` G ) ( C Func D ) ( 2nd ` G ) ) | 
						
							| 28 | 22 5 27 | sylancr |  |-  ( ph -> ( 1st ` G ) ( C Func D ) ( 2nd ` G ) ) | 
						
							| 29 | 2 20 28 | funcf1 |  |-  ( ph -> ( 1st ` G ) : B --> ( Base ` D ) ) | 
						
							| 30 | 29 | ffvelcdmda |  |-  ( ( ph /\ x e. B ) -> ( ( 1st ` G ) ` x ) e. ( Base ` D ) ) | 
						
							| 31 | 20 7 21 26 30 9 | isinv |  |-  ( ( ph /\ x e. B ) -> ( ( U ` x ) ( ( ( 1st ` F ) ` x ) J ( ( 1st ` G ) ` x ) ) ( V ` x ) <-> ( ( U ` x ) ( ( ( 1st ` F ) ` x ) ( Sect ` D ) ( ( 1st ` G ) ` x ) ) ( V ` x ) /\ ( V ` x ) ( ( ( 1st ` G ) ` x ) ( Sect ` D ) ( ( 1st ` F ) ` x ) ) ( U ` x ) ) ) ) | 
						
							| 32 | 31 | ralbidva |  |-  ( ph -> ( A. x e. B ( U ` x ) ( ( ( 1st ` F ) ` x ) J ( ( 1st ` G ) ` x ) ) ( V ` x ) <-> A. x e. B ( ( U ` x ) ( ( ( 1st ` F ) ` x ) ( Sect ` D ) ( ( 1st ` G ) ` x ) ) ( V ` x ) /\ ( V ` x ) ( ( ( 1st ` G ) ` x ) ( Sect ` D ) ( ( 1st ` F ) ` x ) ) ( U ` x ) ) ) ) | 
						
							| 33 |  | r19.26 |  |-  ( A. x e. B ( ( U ` x ) ( ( ( 1st ` F ) ` x ) ( Sect ` D ) ( ( 1st ` G ) ` x ) ) ( V ` x ) /\ ( V ` x ) ( ( ( 1st ` G ) ` x ) ( Sect ` D ) ( ( 1st ` F ) ` x ) ) ( U ` x ) ) <-> ( A. x e. B ( U ` x ) ( ( ( 1st ` F ) ` x ) ( Sect ` D ) ( ( 1st ` G ) ` x ) ) ( V ` x ) /\ A. x e. B ( V ` x ) ( ( ( 1st ` G ) ` x ) ( Sect ` D ) ( ( 1st ` F ) ` x ) ) ( U ` x ) ) ) | 
						
							| 34 | 32 33 | bitrdi |  |-  ( ph -> ( A. x e. B ( U ` x ) ( ( ( 1st ` F ) ` x ) J ( ( 1st ` G ) ` x ) ) ( V ` x ) <-> ( A. x e. B ( U ` x ) ( ( ( 1st ` F ) ` x ) ( Sect ` D ) ( ( 1st ` G ) ` x ) ) ( V ` x ) /\ A. x e. B ( V ` x ) ( ( ( 1st ` G ) ` x ) ( Sect ` D ) ( ( 1st ` F ) ` x ) ) ( U ` x ) ) ) ) | 
						
							| 35 | 34 | anbi2d |  |-  ( ph -> ( ( ( U e. ( F N G ) /\ V e. ( G N F ) ) /\ A. x e. B ( U ` x ) ( ( ( 1st ` F ) ` x ) J ( ( 1st ` G ) ` x ) ) ( V ` x ) ) <-> ( ( U e. ( F N G ) /\ V e. ( G N F ) ) /\ ( A. x e. B ( U ` x ) ( ( ( 1st ` F ) ` x ) ( Sect ` D ) ( ( 1st ` G ) ` x ) ) ( V ` x ) /\ A. x e. B ( V ` x ) ( ( ( 1st ` G ) ` x ) ( Sect ` D ) ( ( 1st ` F ) ` x ) ) ( U ` x ) ) ) ) ) | 
						
							| 36 |  | df-3an |  |-  ( ( U e. ( F N G ) /\ V e. ( G N F ) /\ A. x e. B ( U ` x ) ( ( ( 1st ` F ) ` x ) J ( ( 1st ` G ) ` x ) ) ( V ` x ) ) <-> ( ( U e. ( F N G ) /\ V e. ( G N F ) ) /\ A. x e. B ( U ` x ) ( ( ( 1st ` F ) ` x ) J ( ( 1st ` G ) ` x ) ) ( V ` x ) ) ) | 
						
							| 37 |  | df-3an |  |-  ( ( U e. ( F N G ) /\ V e. ( G N F ) /\ A. x e. B ( U ` x ) ( ( ( 1st ` F ) ` x ) ( Sect ` D ) ( ( 1st ` G ) ` x ) ) ( V ` x ) ) <-> ( ( U e. ( F N G ) /\ V e. ( G N F ) ) /\ A. x e. B ( U ` x ) ( ( ( 1st ` F ) ` x ) ( Sect ` D ) ( ( 1st ` G ) ` x ) ) ( V ` x ) ) ) | 
						
							| 38 |  | 3ancoma |  |-  ( ( V e. ( G N F ) /\ U e. ( F N G ) /\ A. x e. B ( V ` x ) ( ( ( 1st ` G ) ` x ) ( Sect ` D ) ( ( 1st ` F ) ` x ) ) ( U ` x ) ) <-> ( U e. ( F N G ) /\ V e. ( G N F ) /\ A. x e. B ( V ` x ) ( ( ( 1st ` G ) ` x ) ( Sect ` D ) ( ( 1st ` F ) ` x ) ) ( U ` x ) ) ) | 
						
							| 39 |  | df-3an |  |-  ( ( U e. ( F N G ) /\ V e. ( G N F ) /\ A. x e. B ( V ` x ) ( ( ( 1st ` G ) ` x ) ( Sect ` D ) ( ( 1st ` F ) ` x ) ) ( U ` x ) ) <-> ( ( U e. ( F N G ) /\ V e. ( G N F ) ) /\ A. x e. B ( V ` x ) ( ( ( 1st ` G ) ` x ) ( Sect ` D ) ( ( 1st ` F ) ` x ) ) ( U ` x ) ) ) | 
						
							| 40 | 38 39 | bitri |  |-  ( ( V e. ( G N F ) /\ U e. ( F N G ) /\ A. x e. B ( V ` x ) ( ( ( 1st ` G ) ` x ) ( Sect ` D ) ( ( 1st ` F ) ` x ) ) ( U ` x ) ) <-> ( ( U e. ( F N G ) /\ V e. ( G N F ) ) /\ A. x e. B ( V ` x ) ( ( ( 1st ` G ) ` x ) ( Sect ` D ) ( ( 1st ` F ) ` x ) ) ( U ` x ) ) ) | 
						
							| 41 | 37 40 | anbi12i |  |-  ( ( ( U e. ( F N G ) /\ V e. ( G N F ) /\ A. x e. B ( U ` x ) ( ( ( 1st ` F ) ` x ) ( Sect ` D ) ( ( 1st ` G ) ` x ) ) ( V ` x ) ) /\ ( V e. ( G N F ) /\ U e. ( F N G ) /\ A. x e. B ( V ` x ) ( ( ( 1st ` G ) ` x ) ( Sect ` D ) ( ( 1st ` F ) ` x ) ) ( U ` x ) ) ) <-> ( ( ( U e. ( F N G ) /\ V e. ( G N F ) ) /\ A. x e. B ( U ` x ) ( ( ( 1st ` F ) ` x ) ( Sect ` D ) ( ( 1st ` G ) ` x ) ) ( V ` x ) ) /\ ( ( U e. ( F N G ) /\ V e. ( G N F ) ) /\ A. x e. B ( V ` x ) ( ( ( 1st ` G ) ` x ) ( Sect ` D ) ( ( 1st ` F ) ` x ) ) ( U ` x ) ) ) ) | 
						
							| 42 |  | anandi |  |-  ( ( ( U e. ( F N G ) /\ V e. ( G N F ) ) /\ ( A. x e. B ( U ` x ) ( ( ( 1st ` F ) ` x ) ( Sect ` D ) ( ( 1st ` G ) ` x ) ) ( V ` x ) /\ A. x e. B ( V ` x ) ( ( ( 1st ` G ) ` x ) ( Sect ` D ) ( ( 1st ` F ) ` x ) ) ( U ` x ) ) ) <-> ( ( ( U e. ( F N G ) /\ V e. ( G N F ) ) /\ A. x e. B ( U ` x ) ( ( ( 1st ` F ) ` x ) ( Sect ` D ) ( ( 1st ` G ) ` x ) ) ( V ` x ) ) /\ ( ( U e. ( F N G ) /\ V e. ( G N F ) ) /\ A. x e. B ( V ` x ) ( ( ( 1st ` G ) ` x ) ( Sect ` D ) ( ( 1st ` F ) ` x ) ) ( U ` x ) ) ) ) | 
						
							| 43 | 41 42 | bitr4i |  |-  ( ( ( U e. ( F N G ) /\ V e. ( G N F ) /\ A. x e. B ( U ` x ) ( ( ( 1st ` F ) ` x ) ( Sect ` D ) ( ( 1st ` G ) ` x ) ) ( V ` x ) ) /\ ( V e. ( G N F ) /\ U e. ( F N G ) /\ A. x e. B ( V ` x ) ( ( ( 1st ` G ) ` x ) ( Sect ` D ) ( ( 1st ` F ) ` x ) ) ( U ` x ) ) ) <-> ( ( U e. ( F N G ) /\ V e. ( G N F ) ) /\ ( A. x e. B ( U ` x ) ( ( ( 1st ` F ) ` x ) ( Sect ` D ) ( ( 1st ` G ) ` x ) ) ( V ` x ) /\ A. x e. B ( V ` x ) ( ( ( 1st ` G ) ` x ) ( Sect ` D ) ( ( 1st ` F ) ` x ) ) ( U ` x ) ) ) ) | 
						
							| 44 | 35 36 43 | 3bitr4g |  |-  ( ph -> ( ( U e. ( F N G ) /\ V e. ( G N F ) /\ A. x e. B ( U ` x ) ( ( ( 1st ` F ) ` x ) J ( ( 1st ` G ) ` x ) ) ( V ` x ) ) <-> ( ( U e. ( F N G ) /\ V e. ( G N F ) /\ A. x e. B ( U ` x ) ( ( ( 1st ` F ) ` x ) ( Sect ` D ) ( ( 1st ` G ) ` x ) ) ( V ` x ) ) /\ ( V e. ( G N F ) /\ U e. ( F N G ) /\ A. x e. B ( V ` x ) ( ( ( 1st ` G ) ` x ) ( Sect ` D ) ( ( 1st ` F ) ` x ) ) ( U ` x ) ) ) ) ) | 
						
							| 45 | 12 19 44 | 3bitr4d |  |-  ( ph -> ( U ( F I G ) V <-> ( U e. ( F N G ) /\ V e. ( G N F ) /\ A. x e. B ( U ` x ) ( ( ( 1st ` F ) ` x ) J ( ( 1st ` G ) ` x ) ) ( V ` x ) ) ) ) |