Formally, Eq. (33) follows from Eq. (32)
and basic rule 4. Its interpretation is that the probability of
any hypothesis can be seen as `weighted average' of conditional
probabilities, with weights given by the probabilities of the
conditionands [remember that
and therefore Eq. (33)
can be rewritten as
Eq. (34) and (35) are simple extensions
of Eq. (32) and (33) to a generic `complete class',
defined as a set of mutually exclusive hypotheses
[
, i.e.
],
of which at least one must be true [
,
i.e.
]. It follows then that Eq. (35)
can be rewritten as the (`more explicit') weighted average