ebnf-use-float-format is a variable defined in `ebnf2ps.el'.
Its value is

Non-nil means use `%f' float format.

The advantage of using float format is that ebnf2ps generates a little short
PostScript file.

If it occurs the error message:

Invalid format operation %f

when executing ebnf2ps, set `ebnf-use-float-format' to nil.

You can customize this variable.

This variable was introduced, or its default value was changed, in version 20 of Emacs.