1
The quantities F and G differ by an arbitrarily small amount.
It is intuitively clear that the amount by which Sn exceeds zero should follow the exponential distribution.
It contributes half of the amount on the right hand side of (1).
2
[to sth; to doing sth; see also: total, add up] When n=0, (7) just amounts to saying that......
This just amounts to a choice of units.
Consumer spending on those items amounts to \9 billion.