anchor.diff:  ,,,,,,
   ,,,,,,
   "90.  ","Concrete, Magnetite",,,,,
  -"Formula =","-",,"Molecular mass (g/mole) =","Molecular mass (g/mole) =",,"-"
  +"Formula =","-",,"Molecular weight (g/mole) =","Molecular weight (g/mole) =",,"-"
   "Density (g/cm3) =",,3.530000,"Total atom density (atoms/b-cm) =",,,7.970E-02
   "The above density is estimated to be accurate to 2 significant digits.  Dealing with uncertainties is left to the user.",,,,,,
  -"The following data was calculated from the input mass fractions.",,,,,,
  -,,,,,,
  -,,,"Mass","Atom","Atom",
  +"The following data was calculated from the input weight fractions.",,,,,,
  +,,,,,,
  +,,,"Weight","Atom","Atom",
   "Element","Neutron ZA","Photon ZA","Fraction","Fraction","Density",
   "H",1001,1000,0.003113,0.082371,0.006565,
   "O",8016,8000,0.330504,0.551004,0.043914,
  
positive.code: ,,,,,,
  "Total",,,1.000000,1.000000,0.093498,
  ,,,,,,
  "MCNP Form","Mass Fractions",,"Atom Fractions",,"Atom Densities",
  "Neutrons",1001,-0.021782,1001,0.297872,1001,0.027850
  ,8016,-0.568029,8016,0.489362,8016,0.045754
  ,12000,-0.150070,12000,0.085106,12000,0.007957
  
negative.code: ,,,,,,
  "Total",,,1.000000,1.000000,0.084236,
  ,,,,,,
  "MCNP Form","Weight Fractions",,"Atom Fractions",,"Atom Densities",
  "Neutrons",6000,-0.120003,6000,0.200002,6000,0.016847
  ,8016,-0.479554,8016,0.599991,8016,0.050541
  ,20000,-0.400443,20000,0.200007,20000,0.016848
  