Description: The value of the alternative function at a set as argument equals the function's value at this argument. (Contributed by Alexander van der Vekens, 25-May-2017)
Ref | Expression | ||
---|---|---|---|
Assertion | afvvfveq |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | nvelim | ||
2 | 1 | necon2ai | |
3 | afvnufveq | ||
4 | 2 3 | syl |