Description: The range of the double converse of a class is equal to its range (even when that class in not a relation). (Contributed by NM, 8-Apr-2007)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | rncnvcnv | ⊢ ran ◡ ◡ 𝐴 = ran 𝐴 | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | df-rn | ⊢ ran 𝐴 = dom ◡ 𝐴 | |
| 2 | dfdm4 | ⊢ dom ◡ 𝐴 = ran ◡ ◡ 𝐴 | |
| 3 | 1 2 | eqtr2i | ⊢ ran ◡ ◡ 𝐴 = ran 𝐴 |