The description of the free attributes does not contain an example

[kniazkov]

The section that describes free attributes does not contain an example. Again I have to flip forward through the text to find how the hell to write it.
Why not give a simple example like this:

[] > vector
  2 > dx
  3 > dy

Oh, look, here we have a vector, but it contains values that cannot be changed. Probably, in order to create a more useful data structure, we should pass these values there, for example:

[dx dy] > vector

Now dx and dy are also part of a vector, only they must be passed from outside, like this:

vector 2 3 > myVector

[0pdd]

@kniazkov the puzzle #29 is still not solved.