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Description: Functor to a terminal category. (Contributed by Zhi Wang, 17-Oct-2025)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | functermc.d | |- ( ph -> D e. Cat ) |
|
| functermc.e | |- ( ph -> E e. TermCat ) |
||
| functermc.b | |- B = ( Base ` D ) |
||
| functermc.c | |- C = ( Base ` E ) |
||
| functermc.h | |- H = ( Hom ` D ) |
||
| functermc.j | |- J = ( Hom ` E ) |
||
| functermc.f | |- F = ( B X. C ) |
||
| functermc.g | |- G = ( x e. B , y e. B |-> ( ( x H y ) X. ( ( F ` x ) J ( F ` y ) ) ) ) |
||
| Assertion | functermc2 | |- ( ph -> ( D Func E ) = { <. F , G >. } ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | functermc.d | |- ( ph -> D e. Cat ) |
|
| 2 | functermc.e | |- ( ph -> E e. TermCat ) |
|
| 3 | functermc.b | |- B = ( Base ` D ) |
|
| 4 | functermc.c | |- C = ( Base ` E ) |
|
| 5 | functermc.h | |- H = ( Hom ` D ) |
|
| 6 | functermc.j | |- J = ( Hom ` E ) |
|
| 7 | functermc.f | |- F = ( B X. C ) |
|
| 8 | functermc.g | |- G = ( x e. B , y e. B |-> ( ( x H y ) X. ( ( F ` x ) J ( F ` y ) ) ) ) |
|
| 9 | relfunc | |- Rel ( D Func E ) |
|
| 10 | 3 | fvexi | |- B e. _V |
| 11 | 4 | fvexi | |- C e. _V |
| 12 | 10 11 | xpex | |- ( B X. C ) e. _V |
| 13 | 7 12 | eqeltri | |- F e. _V |
| 14 | 10 10 | mpoex | |- ( x e. B , y e. B |-> ( ( x H y ) X. ( ( F ` x ) J ( F ` y ) ) ) ) e. _V |
| 15 | 8 14 | eqeltri | |- G e. _V |
| 16 | 13 15 | relsnop | |- Rel { <. F , G >. } |
| 17 | 1 2 3 4 5 6 7 8 | functermc | |- ( ph -> ( z ( D Func E ) w <-> ( z = F /\ w = G ) ) ) |
| 18 | brsnop | |- ( ( F e. _V /\ G e. _V ) -> ( z { <. F , G >. } w <-> ( z = F /\ w = G ) ) ) |
|
| 19 | 13 15 18 | mp2an | |- ( z { <. F , G >. } w <-> ( z = F /\ w = G ) ) |
| 20 | 17 19 | bitr4di | |- ( ph -> ( z ( D Func E ) w <-> z { <. F , G >. } w ) ) |
| 21 | 9 16 20 | eqbrrdiv | |- ( ph -> ( D Func E ) = { <. F , G >. } ) |