@comment -*-texinfo-*-
@comment $Id$
@comment this file contains the News about Singular versions
@comment Unix
@ifclear VERSION
@include version.texi
@end ifclear

@majorheading NEWS in SINGULAR::PLURAL @value{VERSION}

@ifclear singularmanual
@macro nref{what}
\what\
@end macro
@end ifclear

@ifset singularmanual
@macro nref{what}
@ref{\what\}
@end macro
@end ifset

The current version @value{VERSION} is the second pre-release
of the upcoming release series version 2-1. Therefore, some
command names are still subject to change. 

Singular::Plural version 2-1 is generally much faster than any previous
experimental version of Singular::Plural, due to a rewrite of major parts 
of the @sc{Singular} kernel (e.g., the kernel has a new memory manager
and a new polynomial arithmetic) and due to new and better implemented algorithms (e.g., for two-sided Groebner bases and generally, for computations
in factor algebras).

Besides theses internal changes, Singular::Plural version 2-1 offers many new
features and functionalities.

@heading Efficiency Improvements
The following table shows some timings which compare the efficiency of
@sc{Singular}: Plural version 0-9-9 and @sc{Singular} version 2-1-2. 
All times are in seconds
and were obtained on HP 160 workstation with 512 MB RAM running HP-UX 10.20.

@multitable @columnfractions .50 .20 .20 .15
@item @strong{Example} @tab @strong{0-9} @tab @strong{2-1} @tab @strong{Speedup}
@c @item @uref{http://www.singular.uni-kl.de/Benchmarks/Singular/mora_1.sing,,mora_1} @tab std  @tab 32003,x(1..3),ds @tab 82 @tab 9.4 @tab 8.7

@item AnnFD-sl2-4 @tab 3.34       @tab 0.92    @tab 3.6
@item TwoGB-g2-3  @tab 24577      @tab 165     @tab  149
@item ucha4       @tab 12.9       @tab 8.5     @tab  1.5
@item ucha2       @tab 44.3 hrs @tab 9 hrs @tab  4.9
@end multitable

@heading (Commutative) Factorizing algorithms revisited
Starting with version 2-0-4, we use NTL (of Victor Shoup) for factoring
univariate polynomials. The multivariate factoring code in libfac/factory
does now also work over algebraic extension fields.

@heading General Changes
@table @asis
@item @nref{Emacs user interface}
the recommended interface for using @sc{Singular::Plural}
@item @code{EPlural}
new program for an out-of-the-box, pre-customized Emacs which runs
Plural
@item @nref{The online help system}
choose in which browser the on-line help is displayed;
@*wildcard expansion of help topics
@*new layout of html manual pages
@item @nref{Source code debugger}
interactive debugging of procedures written in the @sc{Singular}
language
@item http://www.singular.uni-kl.de/plural
New WWW home-site of @sc{Plural}
@end table

@heading @sc{Singular::Plural} libraries

@table @asis
@item @nref{lieA_lib} Plural definitions of several series of enveloping algebras of simple Lie algebras
@end table


@heading Internal Changes
@table @asis
@item new data structures for monomials and polynomials
Makes polynomial arithmetic significantly faster: Especially for block -
or weighted orderings.
Bucket representation of polynomials in std and NF;
Ring change during std-related computations
(resulting in more speed and less space consumption).
@item new memory management
Results is less memory usage, faster memory allocation/free, less
fragmentation, much better locality of reference.
@end table