Description: Alternate definition of range. (Contributed by Peter Mazsa, 1-Aug-2018)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | dfrn6 | |- ran R = { x | [ x ] `' R =/= (/) } | 
				
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | df-rn | |- ran R = dom `' R  | 
						|
| 2 | dfdm6 |  |-  dom `' R = { x | [ x ] `' R =/= (/) } | 
						|
| 3 | 1 2 | eqtri |  |-  ran R = { x | [ x ] `' R =/= (/) } |