PROCESSORS_MAP
BEGIN
Multi_Instance_Start
3                   (this line is optional)
POP1   0  2  pop1.in pop1.out  alpha=3 
POP2   3  5  pop2.in pop2.out  beta=5.43e-5 debug=on 
POP3   6  9  pop3.in pop3.out  dynamics=finite_volume beta=100.10 debug=on
Multi_Instance_End
END 
ADD any comments in this line and below.
  for multiple instances in single executable, 
  include component info between Multi_Instance_Start
  and Multi_Instance_End, list the number of components (optional),
  and each instance's relative processor_id in that executable world.
  Up to 5 strings could also be attached in the end to pass input and
  output file names and some other info.  Processor overlap is
  allowed within each multi-component executable but NOT within each
  multi-instance executable.