=centercr
@ []QUERY Q 3.8.1: Find the beginning of a continuous period in which ED
was named Edward, in which he had a constant salary, and which
includes the year 1989.
ANSWER: ``1/1/88.''
CATEGORY: (None, Event, Derived) /
(Containment, Interval, Explicit) /
(=, Constant)
=centercr
@ []QUERY Q 3.8.2: Find the dates, before or after the years 1984 and 1985, when
ED acquired a skill.
ANSWER: ``1/1/82'' and ``4/1/82.''
CATEGORY: (None, Event, Derived) /
(Ordering, Interval, Explicit) /
(=, Constant)
=centercr
@ []QUERY Q 3.8.3: Find ED's unemployment periods when he was not exactly
30 years old.
ANSWER: ``2/1/87 – 3/31/87.''
CATEGORY: (None, Element, Union) /
(Ordering, Interval, User-defined) (Containment, Interval, User-defined) /
(=, Constant)
=centercr
@ []QUERY Q 3.8.4: Find the time periods when DI worked in the department
in which she has been working during all of 1987.
ANSWER: ``1/1/82 – now.''
CATEGORY: (None, Element, Union) /
(Containment, Interval, Explicit) /
(=, Constant)
=centercr
@ []QUERY Q 3.8.5: Find all the dates, between 1/1/83 and 12/31/85, when the Toy
department budget changed.
ANSWER: ``8/1/84.''
CATEGORY: (None, Event, Derived) /
(Containment, Interval, Explicit) (Ordering, Interval, Computed) /
(=, Single) (< >, Single)