This is an inofficial mirror of http://metamath.tirix.org for personal testing of a visualizer extension only.
Description: Splitting for structure powers, part 2: restriction is a group homomorphism. (Contributed by Stefan O'Rear, 24-Jan-2015)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | pwssplit1.y | |- Y = ( W ^s U ) |
|
| pwssplit1.z | |- Z = ( W ^s V ) |
||
| pwssplit1.b | |- B = ( Base ` Y ) |
||
| pwssplit1.c | |- C = ( Base ` Z ) |
||
| pwssplit1.f | |- F = ( x e. B |-> ( x |` V ) ) |
||
| Assertion | pwssplit2 | |- ( ( W e. Grp /\ U e. X /\ V C_ U ) -> F e. ( Y GrpHom Z ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | pwssplit1.y | |- Y = ( W ^s U ) |
|
| 2 | pwssplit1.z | |- Z = ( W ^s V ) |
|
| 3 | pwssplit1.b | |- B = ( Base ` Y ) |
|
| 4 | pwssplit1.c | |- C = ( Base ` Z ) |
|
| 5 | pwssplit1.f | |- F = ( x e. B |-> ( x |` V ) ) |
|
| 6 | eqid | |- ( +g ` Y ) = ( +g ` Y ) |
|
| 7 | eqid | |- ( +g ` Z ) = ( +g ` Z ) |
|
| 8 | simp1 | |- ( ( W e. Grp /\ U e. X /\ V C_ U ) -> W e. Grp ) |
|
| 9 | simp2 | |- ( ( W e. Grp /\ U e. X /\ V C_ U ) -> U e. X ) |
|
| 10 | 1 | pwsgrp | |- ( ( W e. Grp /\ U e. X ) -> Y e. Grp ) |
| 11 | 8 9 10 | syl2anc | |- ( ( W e. Grp /\ U e. X /\ V C_ U ) -> Y e. Grp ) |
| 12 | simp3 | |- ( ( W e. Grp /\ U e. X /\ V C_ U ) -> V C_ U ) |
|
| 13 | 9 12 | ssexd | |- ( ( W e. Grp /\ U e. X /\ V C_ U ) -> V e. _V ) |
| 14 | 2 | pwsgrp | |- ( ( W e. Grp /\ V e. _V ) -> Z e. Grp ) |
| 15 | 8 13 14 | syl2anc | |- ( ( W e. Grp /\ U e. X /\ V C_ U ) -> Z e. Grp ) |
| 16 | 1 2 3 4 5 | pwssplit0 | |- ( ( W e. Grp /\ U e. X /\ V C_ U ) -> F : B --> C ) |
| 17 | offres | |- ( ( a e. B /\ b e. B ) -> ( ( a oF ( +g ` W ) b ) |` V ) = ( ( a |` V ) oF ( +g ` W ) ( b |` V ) ) ) |
|
| 18 | 17 | adantl | |- ( ( ( W e. Grp /\ U e. X /\ V C_ U ) /\ ( a e. B /\ b e. B ) ) -> ( ( a oF ( +g ` W ) b ) |` V ) = ( ( a |` V ) oF ( +g ` W ) ( b |` V ) ) ) |
| 19 | 8 | adantr | |- ( ( ( W e. Grp /\ U e. X /\ V C_ U ) /\ ( a e. B /\ b e. B ) ) -> W e. Grp ) |
| 20 | simpl2 | |- ( ( ( W e. Grp /\ U e. X /\ V C_ U ) /\ ( a e. B /\ b e. B ) ) -> U e. X ) |
|
| 21 | simprl | |- ( ( ( W e. Grp /\ U e. X /\ V C_ U ) /\ ( a e. B /\ b e. B ) ) -> a e. B ) |
|
| 22 | simprr | |- ( ( ( W e. Grp /\ U e. X /\ V C_ U ) /\ ( a e. B /\ b e. B ) ) -> b e. B ) |
|
| 23 | eqid | |- ( +g ` W ) = ( +g ` W ) |
|
| 24 | 1 3 19 20 21 22 23 6 | pwsplusgval | |- ( ( ( W e. Grp /\ U e. X /\ V C_ U ) /\ ( a e. B /\ b e. B ) ) -> ( a ( +g ` Y ) b ) = ( a oF ( +g ` W ) b ) ) |
| 25 | 24 | reseq1d | |- ( ( ( W e. Grp /\ U e. X /\ V C_ U ) /\ ( a e. B /\ b e. B ) ) -> ( ( a ( +g ` Y ) b ) |` V ) = ( ( a oF ( +g ` W ) b ) |` V ) ) |
| 26 | 5 | fvtresfn | |- ( a e. B -> ( F ` a ) = ( a |` V ) ) |
| 27 | 5 | fvtresfn | |- ( b e. B -> ( F ` b ) = ( b |` V ) ) |
| 28 | 26 27 | oveqan12d | |- ( ( a e. B /\ b e. B ) -> ( ( F ` a ) oF ( +g ` W ) ( F ` b ) ) = ( ( a |` V ) oF ( +g ` W ) ( b |` V ) ) ) |
| 29 | 28 | adantl | |- ( ( ( W e. Grp /\ U e. X /\ V C_ U ) /\ ( a e. B /\ b e. B ) ) -> ( ( F ` a ) oF ( +g ` W ) ( F ` b ) ) = ( ( a |` V ) oF ( +g ` W ) ( b |` V ) ) ) |
| 30 | 18 25 29 | 3eqtr4d | |- ( ( ( W e. Grp /\ U e. X /\ V C_ U ) /\ ( a e. B /\ b e. B ) ) -> ( ( a ( +g ` Y ) b ) |` V ) = ( ( F ` a ) oF ( +g ` W ) ( F ` b ) ) ) |
| 31 | 3 6 | grpcl | |- ( ( Y e. Grp /\ a e. B /\ b e. B ) -> ( a ( +g ` Y ) b ) e. B ) |
| 32 | 31 | 3expb | |- ( ( Y e. Grp /\ ( a e. B /\ b e. B ) ) -> ( a ( +g ` Y ) b ) e. B ) |
| 33 | 11 32 | sylan | |- ( ( ( W e. Grp /\ U e. X /\ V C_ U ) /\ ( a e. B /\ b e. B ) ) -> ( a ( +g ` Y ) b ) e. B ) |
| 34 | 5 | fvtresfn | |- ( ( a ( +g ` Y ) b ) e. B -> ( F ` ( a ( +g ` Y ) b ) ) = ( ( a ( +g ` Y ) b ) |` V ) ) |
| 35 | 33 34 | syl | |- ( ( ( W e. Grp /\ U e. X /\ V C_ U ) /\ ( a e. B /\ b e. B ) ) -> ( F ` ( a ( +g ` Y ) b ) ) = ( ( a ( +g ` Y ) b ) |` V ) ) |
| 36 | 13 | adantr | |- ( ( ( W e. Grp /\ U e. X /\ V C_ U ) /\ ( a e. B /\ b e. B ) ) -> V e. _V ) |
| 37 | 16 | ffvelcdmda | |- ( ( ( W e. Grp /\ U e. X /\ V C_ U ) /\ a e. B ) -> ( F ` a ) e. C ) |
| 38 | 37 | adantrr | |- ( ( ( W e. Grp /\ U e. X /\ V C_ U ) /\ ( a e. B /\ b e. B ) ) -> ( F ` a ) e. C ) |
| 39 | 16 | ffvelcdmda | |- ( ( ( W e. Grp /\ U e. X /\ V C_ U ) /\ b e. B ) -> ( F ` b ) e. C ) |
| 40 | 39 | adantrl | |- ( ( ( W e. Grp /\ U e. X /\ V C_ U ) /\ ( a e. B /\ b e. B ) ) -> ( F ` b ) e. C ) |
| 41 | 2 4 19 36 38 40 23 7 | pwsplusgval | |- ( ( ( W e. Grp /\ U e. X /\ V C_ U ) /\ ( a e. B /\ b e. B ) ) -> ( ( F ` a ) ( +g ` Z ) ( F ` b ) ) = ( ( F ` a ) oF ( +g ` W ) ( F ` b ) ) ) |
| 42 | 30 35 41 | 3eqtr4d | |- ( ( ( W e. Grp /\ U e. X /\ V C_ U ) /\ ( a e. B /\ b e. B ) ) -> ( F ` ( a ( +g ` Y ) b ) ) = ( ( F ` a ) ( +g ` Z ) ( F ` b ) ) ) |
| 43 | 3 4 6 7 11 15 16 42 | isghmd | |- ( ( W e. Grp /\ U e. X /\ V C_ U ) -> F e. ( Y GrpHom Z ) ) |