Hello,

I would like to find the element of a vectos above a certain threshold. I am trying with:

```
a = [ 1 2 3 4 3 5 3 6 7 8 9 3 ]
find( x->(x == 3), a)
find(a .== 3
```

but

```
julia> find( x->(x == 3), a)
ERROR: UndefVarError: find not defined
Stacktrace:
[1] top-level scope
@ none:1
julia> find(a .== 3)
ERROR: UndefVarError: find not defined
Stacktrace:
[1] top-level scope
@ none:1
julia> findall( x->(x == 3), a)
4-element Vector{CartesianIndex{2}}:
CartesianIndex(1, 3)
CartesianIndex(1, 5)
CartesianIndex(1, 7)
CartesianIndex(1, 12)
julia> findall(a .== 3)
4-element Vector{CartesianIndex{2}}:
CartesianIndex(1, 3)
CartesianIndex(1, 5)
CartesianIndex(1, 7)
CartesianIndex(1, 12)
```

How do I get the first true element?