In Julia 1.8.3. Given the following two type signatures.

```
(x::AbstractFloat, y::Number)
(x::Union{Float64, ComplexF64}, y::Union{Float64, ComplexF64})
```

I would expect there being an ambiguity error if the input type is `(::Float64, ::Float64)`

.

## But

```
julia> FloatAndComplex64 = Union{Float64, ComplexF64}
Union{Float64, ComplexF64}
julia> begin
function roughly_equal(x::AbstractFloat, y::Number)
@info "(::AbstractFloat, ::Number)"
-10 * eps(x) < x - y < 10 * eps(x)
end
function roughly_equal(x::Union{Float64, ComplexF64}, y::Union{Float64, ComplexF64})
@info "(::Union{Float64, ComplexF64}, ::Union{Float64, ComplexF64})"
abs(x - y) < 10 * eps(y)
end
end
roughly_equal (generic function with 4 methods)
julia> roughly_equal(3.0, 3.0)
[ Info: (::Union{Float64, ComplexF64}, ::Union{Float64, ComplexF64})
true
```