Re: Removed[$$Failure] in Integrate

*To*: mathgroup at smc.vnet.net*Subject*: [mg61966] Re: [mg61928] Removed[$$Failure] in Integrate*From*: danl at wolfram.com*Date*: Sat, 5 Nov 2005 22:41:51 -0500 (EST)*References*: <200511050652.BAA01952@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

> Hi folks > > Has any body come across this while using Integrate > > Removed[$$Failure] > > What does this mean? Besides the obvious explanation > > Please advise > > -- > Pratik Desai > Graduate Student > UMBC > Department of Mechanical Engineering > Phone: 410 455 8134 There really isn't much to say beyond the obvious. $$Failure can be used in internal Integrate code to signify that a method has, well, failed to produce a useful result. Calling procedures are supposed to catch this and either try other methods or give up and return unevaluated. If a caller neglects to do this, it is a bug. Also the Mathematica evaluator eventually notices $$Failure, prior to returning a final result, and attempts the removal that led to the output you describe. If you have specific examples of this in recent versions, you could report them as bugs to support at wolfram.com. Or send them to me, if you prefer. Either way it is best if you simplify the examples to the extent reasonable. Daniel Lichtblau WOlfram Research

**References**:**Removed[$$Failure] in Integrate***From:*Pratik Desai <pdesai1@umbc.edu>