| Step | Hyp | Ref | Expression | 
						
							| 1 |  | dvresntr.s |  |-  ( ph -> S C_ CC ) | 
						
							| 2 |  | dvresntr.x |  |-  ( ph -> X C_ S ) | 
						
							| 3 |  | dvresntr.f |  |-  ( ph -> F : X --> CC ) | 
						
							| 4 |  | dvresntr.j |  |-  J = ( K |`t S ) | 
						
							| 5 |  | dvresntr.k |  |-  K = ( TopOpen ` CCfld ) | 
						
							| 6 |  | dvresntr.i |  |-  ( ph -> ( ( int ` J ) ` X ) = Y ) | 
						
							| 7 | 5 4 | dvres |  |-  ( ( ( S C_ CC /\ F : X --> CC ) /\ ( X C_ S /\ X C_ S ) ) -> ( S _D ( F |` X ) ) = ( ( S _D F ) |` ( ( int ` J ) ` X ) ) ) | 
						
							| 8 | 1 3 2 2 7 | syl22anc |  |-  ( ph -> ( S _D ( F |` X ) ) = ( ( S _D F ) |` ( ( int ` J ) ` X ) ) ) | 
						
							| 9 |  | ffn |  |-  ( F : X --> CC -> F Fn X ) | 
						
							| 10 |  | fnresdm |  |-  ( F Fn X -> ( F |` X ) = F ) | 
						
							| 11 | 3 9 10 | 3syl |  |-  ( ph -> ( F |` X ) = F ) | 
						
							| 12 | 11 | oveq2d |  |-  ( ph -> ( S _D ( F |` X ) ) = ( S _D F ) ) | 
						
							| 13 | 5 | cnfldtopon |  |-  K e. ( TopOn ` CC ) | 
						
							| 14 |  | resttopon |  |-  ( ( K e. ( TopOn ` CC ) /\ S C_ CC ) -> ( K |`t S ) e. ( TopOn ` S ) ) | 
						
							| 15 | 13 1 14 | sylancr |  |-  ( ph -> ( K |`t S ) e. ( TopOn ` S ) ) | 
						
							| 16 | 4 15 | eqeltrid |  |-  ( ph -> J e. ( TopOn ` S ) ) | 
						
							| 17 |  | topontop |  |-  ( J e. ( TopOn ` S ) -> J e. Top ) | 
						
							| 18 | 16 17 | syl |  |-  ( ph -> J e. Top ) | 
						
							| 19 |  | toponuni |  |-  ( J e. ( TopOn ` S ) -> S = U. J ) | 
						
							| 20 | 16 19 | syl |  |-  ( ph -> S = U. J ) | 
						
							| 21 | 2 20 | sseqtrd |  |-  ( ph -> X C_ U. J ) | 
						
							| 22 |  | eqid |  |-  U. J = U. J | 
						
							| 23 | 22 | ntridm |  |-  ( ( J e. Top /\ X C_ U. J ) -> ( ( int ` J ) ` ( ( int ` J ) ` X ) ) = ( ( int ` J ) ` X ) ) | 
						
							| 24 | 18 21 23 | syl2anc |  |-  ( ph -> ( ( int ` J ) ` ( ( int ` J ) ` X ) ) = ( ( int ` J ) ` X ) ) | 
						
							| 25 | 6 | fveq2d |  |-  ( ph -> ( ( int ` J ) ` ( ( int ` J ) ` X ) ) = ( ( int ` J ) ` Y ) ) | 
						
							| 26 | 24 25 6 | 3eqtr3d |  |-  ( ph -> ( ( int ` J ) ` Y ) = Y ) | 
						
							| 27 | 26 | reseq2d |  |-  ( ph -> ( ( S _D F ) |` ( ( int ` J ) ` Y ) ) = ( ( S _D F ) |` Y ) ) | 
						
							| 28 | 22 | ntrss2 |  |-  ( ( J e. Top /\ X C_ U. J ) -> ( ( int ` J ) ` X ) C_ X ) | 
						
							| 29 | 18 21 28 | syl2anc |  |-  ( ph -> ( ( int ` J ) ` X ) C_ X ) | 
						
							| 30 | 6 29 | eqsstrrd |  |-  ( ph -> Y C_ X ) | 
						
							| 31 | 30 2 | sstrd |  |-  ( ph -> Y C_ S ) | 
						
							| 32 | 5 4 | dvres |  |-  ( ( ( S C_ CC /\ F : X --> CC ) /\ ( X C_ S /\ Y C_ S ) ) -> ( S _D ( F |` Y ) ) = ( ( S _D F ) |` ( ( int ` J ) ` Y ) ) ) | 
						
							| 33 | 1 3 2 31 32 | syl22anc |  |-  ( ph -> ( S _D ( F |` Y ) ) = ( ( S _D F ) |` ( ( int ` J ) ` Y ) ) ) | 
						
							| 34 | 6 | reseq2d |  |-  ( ph -> ( ( S _D F ) |` ( ( int ` J ) ` X ) ) = ( ( S _D F ) |` Y ) ) | 
						
							| 35 | 27 33 34 | 3eqtr4rd |  |-  ( ph -> ( ( S _D F ) |` ( ( int ` J ) ` X ) ) = ( S _D ( F |` Y ) ) ) | 
						
							| 36 | 8 12 35 | 3eqtr3d |  |-  ( ph -> ( S _D F ) = ( S _D ( F |` Y ) ) ) |