Metamath Proof Explorer


Theorem 2idlridld

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 ) )

Proof

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 ) )