An intersection interval is a nonempty intersection of any combination of
the given intervals, and a maximal intersection interval is an intersection
interval that contains no other intersection interval.
The Delta matrix is a matrix of indicators (TRUE
or FALSE
).
The rows correspond to the given interval-censored observations, and the
columns the maximal intersection intervals. A TRUE
value of the
(i,j)-th element means that the i-th observation covers the j-th maximal
intersection interval, and a FALSE
value means the opposite.