Description: The preimage of the range of a class is the domain of the class. (Contributed by Jeff Hankins, 15-Jul-2009)
Ref | Expression | ||
---|---|---|---|
Assertion | cnvimarndm | ⊢ ( ◡ 𝐴 “ ran 𝐴 ) = dom 𝐴 |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | imadmrn | ⊢ ( ◡ 𝐴 “ dom ◡ 𝐴 ) = ran ◡ 𝐴 | |
2 | df-rn | ⊢ ran 𝐴 = dom ◡ 𝐴 | |
3 | 2 | imaeq2i | ⊢ ( ◡ 𝐴 “ ran 𝐴 ) = ( ◡ 𝐴 “ dom ◡ 𝐴 ) |
4 | dfdm4 | ⊢ dom 𝐴 = ran ◡ 𝐴 | |
5 | 1 3 4 | 3eqtr4i | ⊢ ( ◡ 𝐴 “ ran 𝐴 ) = dom 𝐴 |