Description: Reflexive equality of sets. The content of x is identical with the content of x . Part of Axiom 54 of Frege1879 p. 50. Slightly specialized version of eqid . (Contributed by RP, 24-Dec-2019) (Proof modification is discouraged.)
Ref | Expression | ||
---|---|---|---|
Assertion | frege54b | |- x = x |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | ax-frege54c | |- x = x |