# `til`


_First x natural numbers_ 
```syntax
til x    til[x]
```

Where `x` is a non-negative integer atom, returns a vector of the first `x` integers. 
```q
q)til 0
`long$()
q)til 1b
,0
q)til 5
0 1 2 3 4
q)til 5f
'type
  [0]  til 5f
       ^
```

`til` and [`key`](key.md) are synonyms, but the above usage is conventionally reserved to `til`.

`til` is a [multithreaded primitive](../kb/mt-primitives.md).

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[Mathematics](../basics/math.md)