  
  [1X1 Introduction[0X
  
  [5XHomalgToCAS[0m is one of the core packages of the [5Xhomalg[0m project [ht09]. But as
  one  of  the  rather  technical  packages,  this  manual  is probably not of
  interest  for  the  average  uers.  The average user will usually not get in
  direct contact with the operations provided by this package.
  
  Quoting  from  the  Appendix  [14X'homalg: The Core Packages and the Idea behind
  their Splitting'[0m of the [5Xhomalg[0m package manual (--> [14X'homalg: HomalgToCAS'[0m):
  
  "The  package [5XHomalgToCAS[0m (which needs the [5Xhomalg[0m package) includes all what
  is  needed to let the black boxes used by [5Xhomalg[0m reside in external computer
  algebra  systems.  So  as mentioned above, [5XHomalgToCAS[0m is the right place to
  declare   the  three  [5XGAP[0m  representations  external  rings,  external  ring
  elements,  and external matrices. Still, [5XHomalgToCAS[0m is independent from the
  external  computer  algebra  system  with  which  [5XGAP[0m  will  communicate [13Xand[0m
  independent of how this communication physically looks like."
  
  
  [1X1.1 [5XHomalgToCAS[1X provides ...[0X
  
  --    Declaration and construction of
  
  --          external   objects  (which  are  pointers  to  data  (rings,ring
              elements, matrices, ...) residing in external systems)
  
  --          external rings (as a new representation for the [5XGAP4[0m-category of
              homalg rings)
  
  --          external   ring  elements  (as  a  new  representation  for  the
              [5XGAP4[0m-category of homalg ring elements)
  
  --          external matrices (as a new representation for the [5XGAP4[0m-category
              of homalg matrices)
  
  --    [10XLaunchCAS[0m:  the  standard  interface used by [5Xhomalg[0m to launch external
        systems
  
  --    [10XTerminateCAS[0m:  the  standard  interface  used  by  [5Xhomalg[0m to terminate
        external systems
  
  --    [10XhomalgSendBlocking[0m:  the  standard  interface  used  by [5Xhomalg[0m to send
        commands to external systems
  
  --    External  garbage  collection: delete the data in the external systems
        that became obsolete for [5Xhomalg[0m
  
  --    [10XhomalgIOMode[0m: decide how much of the communication you want to see
  
