The following snippet of the codice_1 literate program shows how arbitrary descriptive phrases in a natural language are used in a literate program to create macros, which act as new "operators" in the literate programming language, and hide chunks of code or other macros. The mark-up notation consists of double angle brackets ("codice_3") that indicate macros, the "codice_4" symbol which indicates the end of the code section in a noweb file. The "codice_5" symbol stands for the "root", topmost node the literate programming tool will start expanding the web of macros from. Actually, writing out the expanded source code can be done from any section or subsection (i.e. a piece of code designated as "codice_6", with the equal sign), so one literate program file can contain several files with machine source code.