This is an inofficial mirror of http://metamath.tirix.org for personal testing of a visualizer extension only.
Description: A section in the opposite category. (Contributed by Mario Carneiro, 3-Jan-2017)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | oppcsect.b | |- B = ( Base ` C ) |
|
| oppcsect.o | |- O = ( oppCat ` C ) |
||
| oppcsect.c | |- ( ph -> C e. Cat ) |
||
| oppcsect.x | |- ( ph -> X e. B ) |
||
| oppcsect.y | |- ( ph -> Y e. B ) |
||
| oppcsect.s | |- S = ( Sect ` C ) |
||
| oppcsect.t | |- T = ( Sect ` O ) |
||
| Assertion | oppcsect2 | |- ( ph -> ( X T Y ) = `' ( X S Y ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | oppcsect.b | |- B = ( Base ` C ) |
|
| 2 | oppcsect.o | |- O = ( oppCat ` C ) |
|
| 3 | oppcsect.c | |- ( ph -> C e. Cat ) |
|
| 4 | oppcsect.x | |- ( ph -> X e. B ) |
|
| 5 | oppcsect.y | |- ( ph -> Y e. B ) |
|
| 6 | oppcsect.s | |- S = ( Sect ` C ) |
|
| 7 | oppcsect.t | |- T = ( Sect ` O ) |
|
| 8 | 2 1 | oppcbas | |- B = ( Base ` O ) |
| 9 | eqid | |- ( Hom ` O ) = ( Hom ` O ) |
|
| 10 | eqid | |- ( comp ` O ) = ( comp ` O ) |
|
| 11 | eqid | |- ( Id ` O ) = ( Id ` O ) |
|
| 12 | 2 | oppccat | |- ( C e. Cat -> O e. Cat ) |
| 13 | 3 12 | syl | |- ( ph -> O e. Cat ) |
| 14 | 8 9 10 11 7 13 4 5 | sectss | |- ( ph -> ( X T Y ) C_ ( ( X ( Hom ` O ) Y ) X. ( Y ( Hom ` O ) X ) ) ) |
| 15 | relxp | |- Rel ( ( X ( Hom ` O ) Y ) X. ( Y ( Hom ` O ) X ) ) |
|
| 16 | relss | |- ( ( X T Y ) C_ ( ( X ( Hom ` O ) Y ) X. ( Y ( Hom ` O ) X ) ) -> ( Rel ( ( X ( Hom ` O ) Y ) X. ( Y ( Hom ` O ) X ) ) -> Rel ( X T Y ) ) ) |
|
| 17 | 14 15 16 | mpisyl | |- ( ph -> Rel ( X T Y ) ) |
| 18 | relcnv | |- Rel `' ( X S Y ) |
|
| 19 | 18 | a1i | |- ( ph -> Rel `' ( X S Y ) ) |
| 20 | 1 2 3 4 5 6 7 | oppcsect | |- ( ph -> ( f ( X T Y ) g <-> g ( X S Y ) f ) ) |
| 21 | vex | |- f e. _V |
|
| 22 | vex | |- g e. _V |
|
| 23 | 21 22 | brcnv | |- ( f `' ( X S Y ) g <-> g ( X S Y ) f ) |
| 24 | 20 23 | bitr4di | |- ( ph -> ( f ( X T Y ) g <-> f `' ( X S Y ) g ) ) |
| 25 | 17 19 24 | eqbrrdv | |- ( ph -> ( X T Y ) = `' ( X S Y ) ) |