anchor.diff:        let finish = defaultArg finish (x.Count - 1)
         x.SubVector(start, finish - start + 1)
   
  +    /// Sets a slice of a vector starting at a specified index
  +    /// and ending at a specified index (both indices are optional)
  +    /// This method can be used via the x.[start .. finish] <- v syntax
  +    member x.SetSlice(start, finish, values) =
  +      let start = defaultArg start 0
  +      let finish = defaultArg finish (x.Count - 1)
  +      x.SetSubVector(start, finish - start + 1, values)
  +
  +
     // A type extension for the generic matrix type that
     // adds the 'GetSlice' method to allow m.[r1 .. r2, c1 .. c2] syntax
     type MathNet.Numerics.LinearAlgebra.Generic.
  
positive.code:       let rstart = defaultArg rstart 0
        let cfinish = defaultArg cfinish (x.ColumnCount - 1)
        let rfinish = defaultArg rfinish (x.RowCount - 1)
        x.SubMatrix(rstart, rfinish - rstart + 1, cstart, cfinish - cstart + 1)
negative.code: // http://github.com/mathnet/mathnet-numerics
  // http://mathnetnumerics.codeplex.com
  //
  // Copyright (c) 2009-2013 Math.NET
  //
  // Permission is hereby granted, free of charge, to any person
  // obtaining a copy of this software and associated documentation
  