Examples for nested/complex property?

[GF-Huang]

public class ComplexModel {
    public int Number { get; set; }
    public string Name { get; set; }
    public bool IsOK { get; set; }
}

public class ViewModel : ValidatableViewModelBase {
    public ComplexModel Model { get; set; }

    public ViewModel() {
        Validator.AddRule(...) // how to validate Model.Number == 1 && Model.Name == "xxx" && Model.IsOK ?
    }
}