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Description: Two ways to express restriction of range Cartesian product, see also xrnres , xrnres2 . (Contributed by Peter Mazsa, 28-Mar-2020)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | xrnres3 | |- ( ( R |X. S ) |` A ) = ( ( R |` A ) |X. ( S |` A ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | resco | |- ( ( `' ( 1st |` ( _V X. _V ) ) o. R ) |` A ) = ( `' ( 1st |` ( _V X. _V ) ) o. ( R |` A ) ) |
|
| 2 | resco | |- ( ( `' ( 2nd |` ( _V X. _V ) ) o. S ) |` A ) = ( `' ( 2nd |` ( _V X. _V ) ) o. ( S |` A ) ) |
|
| 3 | 1 2 | ineq12i | |- ( ( ( `' ( 1st |` ( _V X. _V ) ) o. R ) |` A ) i^i ( ( `' ( 2nd |` ( _V X. _V ) ) o. S ) |` A ) ) = ( ( `' ( 1st |` ( _V X. _V ) ) o. ( R |` A ) ) i^i ( `' ( 2nd |` ( _V X. _V ) ) o. ( S |` A ) ) ) |
| 4 | df-xrn | |- ( R |X. S ) = ( ( `' ( 1st |` ( _V X. _V ) ) o. R ) i^i ( `' ( 2nd |` ( _V X. _V ) ) o. S ) ) |
|
| 5 | 4 | reseq1i | |- ( ( R |X. S ) |` A ) = ( ( ( `' ( 1st |` ( _V X. _V ) ) o. R ) i^i ( `' ( 2nd |` ( _V X. _V ) ) o. S ) ) |` A ) |
| 6 | resindir | |- ( ( ( `' ( 1st |` ( _V X. _V ) ) o. R ) i^i ( `' ( 2nd |` ( _V X. _V ) ) o. S ) ) |` A ) = ( ( ( `' ( 1st |` ( _V X. _V ) ) o. R ) |` A ) i^i ( ( `' ( 2nd |` ( _V X. _V ) ) o. S ) |` A ) ) |
|
| 7 | 5 6 | eqtri | |- ( ( R |X. S ) |` A ) = ( ( ( `' ( 1st |` ( _V X. _V ) ) o. R ) |` A ) i^i ( ( `' ( 2nd |` ( _V X. _V ) ) o. S ) |` A ) ) |
| 8 | df-xrn | |- ( ( R |` A ) |X. ( S |` A ) ) = ( ( `' ( 1st |` ( _V X. _V ) ) o. ( R |` A ) ) i^i ( `' ( 2nd |` ( _V X. _V ) ) o. ( S |` A ) ) ) |
|
| 9 | 3 7 8 | 3eqtr4i | |- ( ( R |X. S ) |` A ) = ( ( R |` A ) |X. ( S |` A ) ) |