text: An example is shown where GEBIK and GEBIF equations are used to describe the isotopic reactions of  consumption into  according to the simultaneous set of reactions
  These can be rewritten using the notation introduced before as.
  The substrate  has not been included due to its scarcity. In addition, we have not specified the isotopic substitution in the  product of the second and third reactions because  is symmetric. Assuming that the second and third reactions have identical reaction rates , , and , the full GEBIK and GEBIF equations are