21-letter words containing a, f, e, r
- universal disk format — (storage, standard) (UDF) A CD-ROM file system standard that is required for DVD ROMs. UDF is the OSTA's replacement for the ISO 9660 file system used on CD-ROMs, but will be mostly used on DVD. DVD multimedia disks use UDF to contain MPEG audio and video streams. To read DVDs you need a DVD drive, the kernel driver for the drive, MPEG video support, and a UDF driver. DVDs containing both UDF filesystems and ISO 9660 filesystems can be read without UDF support. UDF can also be used by CD-R and CD-RW recorders in packet writing mode.
- university of arizona — (body, education) The University was founded in 1885 as a Land Grant institution with a three-fold mission of teaching, research and public service. Today, the University is one of the top 20 research universities in the nation, with a student enrollment of more than 35,000, a faculty and staff of 12,500, and a 345-acre campus. Address: Tucson, Arizona, USA.
- university of iceland — (body, education) The Home of Fjolnir.
- venus's flower basket — a glass sponge of the genus Euplectella, inhabiting deep waters off the Philippines and Japan, having a cylindrical skeleton formed of an intricate latticework of siliceous spicules.
- virginia (rail) fence — a zigzag fence made of rails laid across one another at the ends
- volunteers of america — a religious reform and relief organization, similar to the Salvation Army, founded in New York City in 1896 by Ballington Booth, son of William Booth, the founder of the Salvation Army. Abbreviation: VOA.
- warm silence software — A small company run by(?) Robin Watts, producing software for the Acorn Archimedes.
- water of constitution — water present in a molecule that cannot be removed without disrupting the molecule.
- weak head normal form — (reduction, theory) (WHNF) A lambda expression is in weak head normal form (WHNF) if it is a head normal form (HNF) or any lambda abstraction. I.e. the top level is not a redex. The term was coined by Simon Peyton Jones to make explicit the difference between head normal form (HNF) and what graph reduction systems produce in practice. A lambda abstraction with a reducible body, e.g. \ x . ((\ y . y+x) 2) is in WHNF but not HNF. To reduce this expression to HNF would require reduction of the lambda body: (\ y . y+x) 2 --> 2+x Reduction to WHNF avoids the name capture problem with its need for alpha conversion of an inner lambda abstraction and so is preferred in practical graph reduction systems. The same principle is often used in strict languages such as Scheme to provide call-by-name evaluation by wrapping an expression in a lambda abstraction with no arguments: D = delay E = \ () . E The value of the expression is obtained by applying it to the empty argument list:
- what the future holds — If you wonder what the future holds, you wonder what will happen in the future.
- whip-and-tongue graft — a graft prepared by cutting both the scion and the stock in a sloping direction and inserting a tongue in the scion into a slit in the stock.
- wildlife photographer — someone that specializes in taking photographs of wild animals, especially in their natural habitats, and plants
- william of malmesbury — William of, William of Malmesbury.
- writ of habeas corpus — law: petition for hearing
- xilinx netlist format — (language, electronics) (XNF) A Hardware Description Language for electronic circuit design, developed by Xilinx, Inc..