Description: Distributive law for restriction over difference. (Contributed by BTernaryTau, 15-Aug-2024)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | resdifdir | |- ( ( A \ B ) |` C ) = ( ( A |` C ) \ ( B |` C ) ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | indifdir | |- ( ( A \ B ) i^i ( C X. _V ) ) = ( ( A i^i ( C X. _V ) ) \ ( B i^i ( C X. _V ) ) ) | |
| 2 | df-res | |- ( ( A \ B ) |` C ) = ( ( A \ B ) i^i ( C X. _V ) ) | |
| 3 | df-res | |- ( A |` C ) = ( A i^i ( C X. _V ) ) | |
| 4 | df-res | |- ( B |` C ) = ( B i^i ( C X. _V ) ) | |
| 5 | 3 4 | difeq12i | |- ( ( A |` C ) \ ( B |` C ) ) = ( ( A i^i ( C X. _V ) ) \ ( B i^i ( C X. _V ) ) ) | 
| 6 | 1 2 5 | 3eqtr4i | |- ( ( A \ B ) |` C ) = ( ( A |` C ) \ ( B |` C ) ) |