This is an inofficial mirror of http://metamath.tirix.org for personal testing of a visualizer extension only.
Description: Composition in the category restriction. (Contributed by Mario Carneiro, 4-Jan-2017) (Proof shortened by AV, 13-Oct-2024)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | rescbas.d | |- D = ( C |`cat H ) |
|
| rescbas.b | |- B = ( Base ` C ) |
||
| rescbas.c | |- ( ph -> C e. V ) |
||
| rescbas.h | |- ( ph -> H Fn ( S X. S ) ) |
||
| rescbas.s | |- ( ph -> S C_ B ) |
||
| rescco.o | |- .x. = ( comp ` C ) |
||
| Assertion | rescco | |- ( ph -> .x. = ( comp ` D ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | rescbas.d | |- D = ( C |`cat H ) |
|
| 2 | rescbas.b | |- B = ( Base ` C ) |
|
| 3 | rescbas.c | |- ( ph -> C e. V ) |
|
| 4 | rescbas.h | |- ( ph -> H Fn ( S X. S ) ) |
|
| 5 | rescbas.s | |- ( ph -> S C_ B ) |
|
| 6 | rescco.o | |- .x. = ( comp ` C ) |
|
| 7 | ccoid | |- comp = Slot ( comp ` ndx ) |
|
| 8 | slotsbhcdif | |- ( ( Base ` ndx ) =/= ( Hom ` ndx ) /\ ( Base ` ndx ) =/= ( comp ` ndx ) /\ ( Hom ` ndx ) =/= ( comp ` ndx ) ) |
|
| 9 | simp3 | |- ( ( ( Base ` ndx ) =/= ( Hom ` ndx ) /\ ( Base ` ndx ) =/= ( comp ` ndx ) /\ ( Hom ` ndx ) =/= ( comp ` ndx ) ) -> ( Hom ` ndx ) =/= ( comp ` ndx ) ) |
|
| 10 | 9 | necomd | |- ( ( ( Base ` ndx ) =/= ( Hom ` ndx ) /\ ( Base ` ndx ) =/= ( comp ` ndx ) /\ ( Hom ` ndx ) =/= ( comp ` ndx ) ) -> ( comp ` ndx ) =/= ( Hom ` ndx ) ) |
| 11 | 8 10 | ax-mp | |- ( comp ` ndx ) =/= ( Hom ` ndx ) |
| 12 | 7 11 | setsnid | |- ( comp ` ( C |`s S ) ) = ( comp ` ( ( C |`s S ) sSet <. ( Hom ` ndx ) , H >. ) ) |
| 13 | 2 | fvexi | |- B e. _V |
| 14 | 13 | ssex | |- ( S C_ B -> S e. _V ) |
| 15 | 5 14 | syl | |- ( ph -> S e. _V ) |
| 16 | eqid | |- ( C |`s S ) = ( C |`s S ) |
|
| 17 | 16 6 | ressco | |- ( S e. _V -> .x. = ( comp ` ( C |`s S ) ) ) |
| 18 | 15 17 | syl | |- ( ph -> .x. = ( comp ` ( C |`s S ) ) ) |
| 19 | 1 3 15 4 | rescval2 | |- ( ph -> D = ( ( C |`s S ) sSet <. ( Hom ` ndx ) , H >. ) ) |
| 20 | 19 | fveq2d | |- ( ph -> ( comp ` D ) = ( comp ` ( ( C |`s S ) sSet <. ( Hom ` ndx ) , H >. ) ) ) |
| 21 | 12 18 20 | 3eqtr4a | |- ( ph -> .x. = ( comp ` D ) ) |