This is an inofficial mirror of http://metamath.tirix.org for personal testing of a visualizer extension only.
Description: The "natural forgetful functor" from the category of extensible structures into the category of sets which sends each extensible structure to its base set, preserving the morphisms as mappings between the corresponding base sets. (Contributed by AV, 23-Mar-2020)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | funcestrcsetc.e | |- E = ( ExtStrCat ` U ) |
|
| funcestrcsetc.s | |- S = ( SetCat ` U ) |
||
| funcestrcsetc.b | |- B = ( Base ` E ) |
||
| funcestrcsetc.c | |- C = ( Base ` S ) |
||
| funcestrcsetc.u | |- ( ph -> U e. WUni ) |
||
| funcestrcsetc.f | |- ( ph -> F = ( x e. B |-> ( Base ` x ) ) ) |
||
| funcestrcsetc.g | |- ( ph -> G = ( x e. B , y e. B |-> ( _I |` ( ( Base ` y ) ^m ( Base ` x ) ) ) ) ) |
||
| Assertion | funcestrcsetc | |- ( ph -> F ( E Func S ) G ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | funcestrcsetc.e | |- E = ( ExtStrCat ` U ) |
|
| 2 | funcestrcsetc.s | |- S = ( SetCat ` U ) |
|
| 3 | funcestrcsetc.b | |- B = ( Base ` E ) |
|
| 4 | funcestrcsetc.c | |- C = ( Base ` S ) |
|
| 5 | funcestrcsetc.u | |- ( ph -> U e. WUni ) |
|
| 6 | funcestrcsetc.f | |- ( ph -> F = ( x e. B |-> ( Base ` x ) ) ) |
|
| 7 | funcestrcsetc.g | |- ( ph -> G = ( x e. B , y e. B |-> ( _I |` ( ( Base ` y ) ^m ( Base ` x ) ) ) ) ) |
|
| 8 | eqid | |- ( Hom ` E ) = ( Hom ` E ) |
|
| 9 | eqid | |- ( Hom ` S ) = ( Hom ` S ) |
|
| 10 | eqid | |- ( Id ` E ) = ( Id ` E ) |
|
| 11 | eqid | |- ( Id ` S ) = ( Id ` S ) |
|
| 12 | eqid | |- ( comp ` E ) = ( comp ` E ) |
|
| 13 | eqid | |- ( comp ` S ) = ( comp ` S ) |
|
| 14 | 1 | estrccat | |- ( U e. WUni -> E e. Cat ) |
| 15 | 5 14 | syl | |- ( ph -> E e. Cat ) |
| 16 | 2 | setccat | |- ( U e. WUni -> S e. Cat ) |
| 17 | 5 16 | syl | |- ( ph -> S e. Cat ) |
| 18 | 1 2 3 4 5 6 | funcestrcsetclem3 | |- ( ph -> F : B --> C ) |
| 19 | 1 2 3 4 5 6 7 | funcestrcsetclem4 | |- ( ph -> G Fn ( B X. B ) ) |
| 20 | 1 2 3 4 5 6 7 | funcestrcsetclem8 | |- ( ( ph /\ ( a e. B /\ b e. B ) ) -> ( a G b ) : ( a ( Hom ` E ) b ) --> ( ( F ` a ) ( Hom ` S ) ( F ` b ) ) ) |
| 21 | 1 2 3 4 5 6 7 | funcestrcsetclem7 | |- ( ( ph /\ a e. B ) -> ( ( a G a ) ` ( ( Id ` E ) ` a ) ) = ( ( Id ` S ) ` ( F ` a ) ) ) |
| 22 | 1 2 3 4 5 6 7 | funcestrcsetclem9 | |- ( ( ph /\ ( a e. B /\ b e. B /\ c e. B ) /\ ( h e. ( a ( Hom ` E ) b ) /\ k e. ( b ( Hom ` E ) c ) ) ) -> ( ( a G c ) ` ( k ( <. a , b >. ( comp ` E ) c ) h ) ) = ( ( ( b G c ) ` k ) ( <. ( F ` a ) , ( F ` b ) >. ( comp ` S ) ( F ` c ) ) ( ( a G b ) ` h ) ) ) |
| 23 | 3 4 8 9 10 11 12 13 15 17 18 19 20 21 22 | isfuncd | |- ( ph -> F ( E Func S ) G ) |