Metamath Proof Explorer

Theorem dfid2OLD

Description: Obsolete version of dfid2 as of 4-Nov-2024. (Contributed by NM, 15-Mar-2007) (Proof modification is discouraged.) (New usage is discouraged.)

Ref Expression
Assertion dfid2OLD 
|- _I = { <. x , x >. | x = x }

Proof

Step Hyp Ref Expression
1 dfid3 
 |-  _I = { <. x , x >. | x = x }