## descr -- Prints a description of current preconditioner

    call prec%descr()
    call prec%descr(iout, root)

Type:
  Asynchronous.
On Entry
prec
  the preconditioner. Scope: local
  Type: required
  Intent: in.
  Specified as: a preconditioner data structure precdata`psb_prec_type`.
iout
  output unit. Scope: local
  Type: optional
  Intent: in.
  Specified as: an integer number. Default: default output unit.
root
  Process from which to print Scope: local
  Type: optional
  Intent: in.
  Specified as: an integer number between 0 and , in which case the specified process will print the description, or , in which case all processes will print. Default: 0.