Description: A two-sided ideal is a right ideal. (Contributed by Thierry Arnoux, 9-Mar-2025)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | 2idllidld.1 | |- ( ph -> I e. ( 2Ideal ` R ) ) |
|
| 2idlridld.o | |- O = ( oppR ` R ) |
||
| Assertion | 2idlridld | |- ( ph -> I e. ( LIdeal ` O ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | 2idllidld.1 | |- ( ph -> I e. ( 2Ideal ` R ) ) |
|
| 2 | 2idlridld.o | |- O = ( oppR ` R ) |
|
| 3 | eqid | |- ( LIdeal ` R ) = ( LIdeal ` R ) |
|
| 4 | eqid | |- ( LIdeal ` O ) = ( LIdeal ` O ) |
|
| 5 | eqid | |- ( 2Ideal ` R ) = ( 2Ideal ` R ) |
|
| 6 | 3 2 4 5 | 2idlval | |- ( 2Ideal ` R ) = ( ( LIdeal ` R ) i^i ( LIdeal ` O ) ) |
| 7 | 1 6 | eleqtrdi | |- ( ph -> I e. ( ( LIdeal ` R ) i^i ( LIdeal ` O ) ) ) |
| 8 | 7 | elin2d | |- ( ph -> I e. ( LIdeal ` O ) ) |