A rule disallowed in modules has been encountered.

#2156   Compile-time error

A rule disallowed in modules has been encountered.

Additional Information

The rule is 'X'.

Explanation

Certain rules and declarations are allowed only in the main program. These are process, break-width, no-default-io, data-letters, declare #main-output has, declare #error has, declare #main-input has, declare #process-input has, declare #process-output has, binary-input, binary-output, delimiter, and symbol.