Paraphrasing a colleague of mine: If the interval [09:00,09:00) can be considered the empty set in discrete maths, then - Every interval contains the empty interval (a set contains another set if it contains all the other set's elements) - The empty interval does not overlap any other interval (two sets overlap if their intersection is non-empty) - No interval abuts the empty interval (a set abuts another set if the intersection of the two without the edge value is empty, and the intersection of the two with the edge value is non-empty)
As you said yourself, it all depends on just how the empty interval is defined. The above would work for me. Barend -----Oorspronkelijk bericht----- Van: [EMAIL PROTECTED] Namens Stephen Colebourne Verzonden: woensdag 5 juli 2006 1:04 Aan: Discussion of the Joda project Onderwerp: [Joda-interest] Release 1.3 In case anyone is wondering, I've been trying to tidy up loose ends to finally get this out. The first loose end was the 'find next' concept. This sounded easy, but is in fact very hard. The problem is with DST shifts, where the same time appears twice in quick succession. For now, I've shelved this work. The second loose end is trying to work out if a previous bug fix for empty intervals was valid. Are there any mathematicians present? Consider an interval from 09:00 to 10:00. Its half-open - [09:00,10:00). Does this interval contain an empty interval [09:00,09:00) ? Does this interval abut an empty interval [09:00,09:00) ? Does this interval overlap an empty interval [09:00,09:00) ? As far as I can tell, there is no 'right' answer to this as an empty interval is rather ill-defined. Do you consider it as a point on the timeline (thus it is contained and abuts). Or do you consider it as starting at and excluding 09:00 (thus it is not contained as it excludes 09:00, but does abut) Any of this make any sense? Anyone know interval theory? Stephen _______________________________________________ Joda-interest mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/joda-interest Disclaimer: This message contains information that may be privileged or confidential and is the property of Sogeti Nederland B.V. or its Group members. It is intended only for the person to whom it is addressed. If you are not the intended recipient, you are not authorized to read, print, retain, copy, disseminate, distribute, or use this message or any part thereof. If you receive this message in error, please notify the sender immediately and delete all copies of this message. Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ Joda-interest mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/joda-interest
