Halliday & Matthiessen (2014: 474):
Hypotactic clauses of addition are introduced by the conjunctions whereas, while. There is no clear line between the (positive) additive and the adversative; these clauses sometimes have an adversative component, sometimes not. (There is no negative additive type of hypotactic extension.) For example:||| Whereas most children’s fathers worked at an office, || my father worked at the studio, || so I went on the set. |||
||| They have no patience with our official style or tempo, || whereas an Indian at home would accept the hurdles as inevitable Karma. |||
||| And yet Frank grows up, || while Huck never grew up. |||
||| He will be an institutional dealer in New York, || while Mr Hayward will be an equity salesman. |||
||| While ‘Joe Gould’s Secret’ and ‘The Sweet Hereafter’ played to small audiences in limited release, || Holm has a couple of potential blockbusters [[ coming up]] . |||