The function 'X' was first predefined on line N of file 'F'. The conversion function was first predefined on line N of file 'F'.
in case the function was predefined with define conversion-function.
Compilation continues but no compiled source code file will be saved.
All functions must be declared before they are used. The body of the function may be given anywhere in a
program (thereby defining the function), but its heading must appear at least once before its first use.