skill: context build error

[sc]

Hi,
I'm trying to build context file but get the next error messages:
*Error* eval: undefined function - defmacro
*Error* eval: undefined function - defstruct
I use procedures from "SKILL Language User Guide" (Delivering Products-

Contexts->Creating Unility Functions).
How can I find and understand the reason of these errors? Please help.

Any suggestion is highly appreciated.
Thanks