anchor.diff:  let testing_samples = [| [ 0.692; 0.000; 0.000; 0.174; 0.000; 0.000; 0.000; ] |]
   let teaching_samples_inputs = [| [ 1.0; 0.0; 0.0; 0.0; 0.0; 0.0; 0.0; 0.0; 0.0; 0.0; 1.0; 0.0; 0.0;  ] |]
   
  -let epoch = 1
  +let epoch = 100
   
   let trained =
    train
  
positive.code: let addVectors xs ys    = List.map2 (+) xs ys
  let logSigmoid x        = (/) 1.0 ((+) 1.0 (exp -x))
  let dervLogSigmoid x    = (*) x ((-) 1.0 x)
  let dervTanH x          = (*) (1.0 - x) (1.0 + x)
  let gradient dFunc output target = (*) (dFunc output) ((-) target output)
  
  let weightedSum inputs weights bias =
  
negative.code: 
  /// Maps a scalar to a vector using a mapper function.
  let scalarToVecOp mapper x ys = List.map (mapper x) ys
  
  let rec f2 mapper xs ys = //***normalize
   match xs with
   | [] -> []
  