Function: ebnf-eps-region

Generate a PostScript syntactic chart image of the region in an EPS file.

Generate an EPS file for each production in the region.
The EPS file name has the following form:

.eps

is given by variable `ebnf-eps-prefix'.
The default value is "ebnf--".

is the production name.
Some characters in the production file name are replaced to
produce a valid file name. For example, the production name
"A/B + C" is modified to produce "A_B_+_C", and the EPS
file name used in this case will be "ebnf--A_B_+_C.eps".

WARNING: This function does *NOT* ask any confirmation to override existing files. (fn FROM TO)