Anonymous record type inside discriminated union

You can define mutually dependent types using and:

    type Employee = 
    | Engineer  of Person
    | Manager   of Manager            // manager has list of reports
    | Executive of Executive
    and Manager = { Name: Person; Reports: Employee list }
    and Executive = { Name: Person; Reports: Employee list; Assistant: Employee }

If you're using F# v3.1 you can use named union fields ^[MSDN] (and protect your delicate sensibilities):

type Employee = 
    | Engineer  of Person
    | Manager   of Name: Person * Reports: Employee list
    | Executive of Name: Person * Reports: Employee list * Assistant: Employee