RosettaCodeData/Task/First-class-functions-Use-numbers-analogously/J/first-class-functions-use-numbers-analogously-1.j

   x          =:  2.0
   xi         =:  0.5
   y          =:  4.0
   yi         =:  0.25
   z          =:  x + y
   zi         =:  1.0 % (x + y)  NB. / is spelled % in J

   fwd        =:  x ,y ,z
   rev        =:  xi,yi,zi

   multiplier =:  2 : 'm * n * ]'