Yet Another Cohomology Program
Status: planning
Abstract
Yacop allows to resolve sub Hopf algebras
of the Steenrod algebra at small primes.
It can compute chain maps and Ext/Tor for small
(differential) Amodules.
It contains a graphical chart viewer that
can also create postscript charts.
Project details
Status:
All the basic stuff is working but a couple
of things are still missing:
 Framework for differential Steenrod algebra modules not finished.
 Regression test suite needs to be created.
 Tor/Ext framework is missing
Installation (preview):
The supported platforms are Linux and MacOS.
Solaris should also work when Sage eventually supports it.
 Download and install sage version 4.6.1
 On Linux make sure you have the file/usr/include/X11/Xlib.h
You might have to install the "libx11dev"
package to get this file.

Download the files
"tcltk8.5.9decarbon.spkg", "yacop1.0.spkg", "15206.patch"
from the links above.

Install the sage packages "tcltk8.5.9decarbon.spkg", "yacop1.0.spkg"
via
./sage f s tcltk8.5.9decarbon.spkg
./sage f s yacop1.0.spkg 

Install the Yacop/Sage patch from the sage prompt via
sage: hg_sage.patch("15206.patch") 

Rebuild the sage index and documentation via
./sage b
./sage docbuild reference html 
You should then find the documentation of the Yacop features
under
devel/sage/doc/output/html/en/reference/algebras.html Example:
Here's a little sample session:
cn@jehova:/waste/cn/sage4.6.1> ./sage

 Sage Version 4.6.1, Release Date: 20110111 
 Type notebook() for the GUI, and license() for information. 

Loading Sage library. Current Mercurial branch is: yacoprelease
sage: C=SteenrodAlgebraGroundFieldResolution(SteenrodAlgebra(5))
sage: # compute a resolution
sage: time C.extend(s=30,n=500)
CPU times: user 79.43 s, sys: 6.26 s, total: 85.69 s
Wall time: 90.10 s
sage: # look at some Ext groups
sage: C.generators(n=453)
{g(9,453), g(12,453), g(22,453), g(3,453), g(29,453), g(11,453), g(18,453)}
sage: # open chart viewer
sage: C.gui() 
Here's a screenshot of the chart viewer: