This is an inofficial mirror of http://metamath.tirix.org for personal testing of a visualizer extension only.
Description: The universal property for the universal pair <. X , M >. from a functor to an object, expressed explicitly. (Contributed by Zhi Wang, 4-Nov-2025)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | oppcup3.b | |- B = ( Base ` D ) |
|
| oppcup3.h | |- H = ( Hom ` D ) |
||
| oppcup3.j | |- J = ( Hom ` E ) |
||
| oppcup3.xb | |- .xb = ( comp ` E ) |
||
| oppcup3.o | |- O = ( oppCat ` D ) |
||
| oppcup3.p | |- P = ( oppCat ` E ) |
||
| oppcup3.x | |- ( ph -> X ( <. F , T >. ( O UP P ) W ) M ) |
||
| oppcup3.g | |- ( ph -> tpos T = G ) |
||
| oppcup3.y | |- ( ph -> Y e. B ) |
||
| oppcup3.n | |- ( ph -> N e. ( ( F ` Y ) J W ) ) |
||
| Assertion | oppcup3 | |- ( ph -> E! k e. ( Y H X ) N = ( M ( <. ( F ` Y ) , ( F ` X ) >. .xb W ) ( ( Y G X ) ` k ) ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | oppcup3.b | |- B = ( Base ` D ) |
|
| 2 | oppcup3.h | |- H = ( Hom ` D ) |
|
| 3 | oppcup3.j | |- J = ( Hom ` E ) |
|
| 4 | oppcup3.xb | |- .xb = ( comp ` E ) |
|
| 5 | oppcup3.o | |- O = ( oppCat ` D ) |
|
| 6 | oppcup3.p | |- P = ( oppCat ` E ) |
|
| 7 | oppcup3.x | |- ( ph -> X ( <. F , T >. ( O UP P ) W ) M ) |
|
| 8 | oppcup3.g | |- ( ph -> tpos T = G ) |
|
| 9 | oppcup3.y | |- ( ph -> Y e. B ) |
|
| 10 | oppcup3.n | |- ( ph -> N e. ( ( F ` Y ) J W ) ) |
|
| 11 | 9 1 | eleqtrdi | |- ( ph -> Y e. ( Base ` D ) ) |
| 12 | 11 | elfvexd | |- ( ph -> D e. _V ) |
| 13 | 10 | ne0d | |- ( ph -> ( ( F ` Y ) J W ) =/= (/) ) |
| 14 | fvprc | |- ( -. E e. _V -> ( Hom ` E ) = (/) ) |
|
| 15 | 3 14 | eqtrid | |- ( -. E e. _V -> J = (/) ) |
| 16 | 15 | oveqd | |- ( -. E e. _V -> ( ( F ` Y ) J W ) = ( ( F ` Y ) (/) W ) ) |
| 17 | 0ov | |- ( ( F ` Y ) (/) W ) = (/) |
|
| 18 | 16 17 | eqtrdi | |- ( -. E e. _V -> ( ( F ` Y ) J W ) = (/) ) |
| 19 | 18 | necon1ai | |- ( ( ( F ` Y ) J W ) =/= (/) -> E e. _V ) |
| 20 | 13 19 | syl | |- ( ph -> E e. _V ) |
| 21 | 7 6 5 12 20 8 | oppcuprcl2 | |- ( ph -> F ( D Func E ) G ) |
| 22 | 7 8 | uptpos | |- ( ph -> X ( <. F , tpos G >. ( O UP P ) W ) M ) |
| 23 | 1 2 3 4 5 6 21 22 | oppcup2 | |- ( ph -> A. y e. B A. g e. ( ( F ` y ) J W ) E! k e. ( y H X ) g = ( M ( <. ( F ` y ) , ( F ` X ) >. .xb W ) ( ( y G X ) ` k ) ) ) |
| 24 | 23 9 10 | oppcup3lem | |- ( ph -> E! k e. ( Y H X ) N = ( M ( <. ( F ` Y ) , ( F ` X ) >. .xb W ) ( ( Y G X ) ` k ) ) ) |