[julia-users] Is the accuracy of Julia's elementary functions (exp, sin ..) known?

[Jeffrey Sarnoff]

```
julia> x, exp(x), Float64(exp(big(x)))
(0.05489354701373524,1.0564281487582248,1.0564281487582246)
```
Is it known that e.g. all elementary functions return a value v such that 
 true value is in: prevfloat(v)..nextfloat(v)?
Are tighter results known for some functions?