Authors Thomas Wolf, Andreas Brand
Short description The package CRACK attempts to solve an overdetermined system of ordinary or partial differential equations (ODEs/PDEs) with at most polynomial non-linearities in the unknown functions and their derivatives. It can be run in automatic batch mode or interactively. Applications of CRACK include a program CONLAW for the computation of conservation laws of DEs, a program LIEPDE for the computation of infinitesimal symmetries of DEs and a program APPLYSYM for the computation of symmetry and similarity variables from infinitesimal symmetries.
Platform REDUCE, version 3.6, 3.7 or 3.8
System requirements The memory requirements depend crucially on the application. For example, the test files crack.tst, applysym.tst, have been run in a 4MB session under LINUX. On the other hand, for more complex examples in liepde.tst and conlaw.tst 4MB are not enough but 8MB are.
CRACK and related programs have been tested under the Portable Standard LISP (PSL) version and the Codemist Standard Lisp (CSL) version of REDUCE.
Installation In a running REDUCE session either do
  in "crack.red"$
or, in order to speed up computation, either compile it with
  on comp$
before the above command, or, generate a fast-loading compiled file once with
  faslout "crack"$
  in "crack.red"$
and load that file whenever you want to run CRACK with
  load crack$
The above commands assume all files to be in the current directory.
More information/updates There are available a manual, a test file and a log file.
CRACK can be run from a web demo created by Francis Wright and Arrigo Triulzi with problems of restricted size.
The latest version is available from http://lie.math.brocku.ca/crack/src/.
Publications related to CRACK can be found here.
Contact e-mail: Thomas Wolf