anchor.diff:  write(stderr,*)
   write(stderr,*) '-flt FLTFILE         Triangular source faults'
   write(stderr,*) '-sta STAFILE         Station/receiver locations'
  -write(stderr,*) '-trg TRGFILE         Target/receiver kinematics'
  +write(stderr,*) '-trg TRGFILE         Target/receiver geometry'
   write(stderr,*) '-haf HAFSPCFILE      Elastic half-space properties'
   write(stderr,*) '-disp DSPFILE        Displacement (E N Z)'
   write(stderr,*) '-strain STNFILE      Strain matrix (EE NN ZZ EN EZ NZ)'
   write(stderr,*) '-stress STSFILE      Stress matrix (EE NN ZZ EN EZ NZ)'
   write(stderr,*) '-estress ESTSFILE    Effective (maximum) shear stress'
   write(stderr,*) '-normal NORFILE      Normal traction on target faults (requires -trg)'
  -write(stderr,*) '-shear[max] SHRFILE  Shear traction on target faults (requires -trg)'
  +write(stderr,*) '-shear SHRFILE       Shear traction on target faults (requires -trg)'
   write(stderr,*) '-coul COULFILE       Coulomb stress on target faults (requires -trg)'
   write(stderr,*) '-geo|-xy             Use geographic (default) or cartesian coordinates'
   write(stderr,*)
  +write(stderr,*) 'See man page for details'
  +write(stderr,*)
   
   stop
   end subroutine usage
  
positive.code: verbosity = 0
  
  narg = command_argument_count()
  if (narg.eq.0) call usage('')
  
  ! Everything is hunky-dory to start out
  ios = 0
  
negative.code: 
  return
  end subroutine calc_strain
  
  !--------------------------------------------------------------------------------------------------!
  
  