where is Async.BuildPrimitive and Async.Spawn defined?

Question

Working through Expert F# and it uses some examples that use Async.BuildPrimitive and Async.Spawn however they are undefined. I am using .NET 4.0.

Answer 1

Library API was changed since publishing the first edition of "Expert F#"

Async.BuildPrimitive -> Async.FromBeginEnd

Async.Spawn -> Async.Start