I am using following notation in which first two nimbers are nat and third one is nat list. First i want to extract list from notation secondly, want to write 4 exist in list l. What commands i should apply?

```
X(nat; nat; nat list)
X(nat;nat;(4::t))
l=(4::t)
In 4 l
```

Last updated: Jun 13 2024 at 21:01 UTC