, then
must have an infinite number of members and there can be no event which is extended over by every member of
. For any member of
, however small, extends over some member of
. The usual case of covering is when both classes,
, then
must have an infinite number of members and there can be no event which is extended over by every member of
. For any member of
, however small, extends over some member of
. The usual case of covering is when both classes,