Data-parallel example: initialization

  Procs p = new Procs(this, 2, 2) ;

  Range x = new Range(N, p, 0) ;  // distrib over 1st dim of `p'
  Range y = new Range(N, p, 1) ;  // distrib over 2nd dim of `p'

  Array r = new Array(p, x, y) ;

  byte [] w = new byte [r.seg()] ;  // main data array

  ... declare neighbour arrays, `cn_', `cp_', etc, similarly

  // initialize the ``life'' board

  for(r.forall() ; r.test() ; r.next())
    w [r.sub()] = fun(x.idx(), y.idx()) ;