This is an inofficial mirror of http://metamath.tirix.org for personal testing of a visualizer extension only.
Metamath Proof Explorer
Description: A function maps to its range. (Contributed by Glauco Siliprandi, 3-Mar-2021)
|
|
Ref |
Expression |
|
Assertion |
ffrn |
|
Proof
| Step |
Hyp |
Ref |
Expression |
| 1 |
|
ffn |
|
| 2 |
|
dffn3 |
|
| 3 |
1 2
|
sylib |
|