Hello,

I define the following two methods:

```
u = [[1,1,1,1], [5,5]]
f(u::Vector{<:Number}) = println("here!")
f(u::Vector{Vector{<:Number}}) = println("there!")
```

Dispatching f() on a vector of numbers works.

```
f(u[1])
here!
```

Dispatching on a vector of vectors of numbers does not

```
f(u)
MethodError: no method matching f(::Array{Array{Int64,1},1})
Closest candidates are:
f(!Matched::Array{Array{#s1,1} where #s1<:Number,1})
f(!Matched::Array{#s1,1} where #s1<:Number)
```

although

```
Int64 <: Number
true
```

I went through the manual but the above behaviour remains unclear.

Thanks in advance.

Jan