 always many different grammars G that would
generate L, but each grammar G generates only one language.

analogue would be:  many theories for each world of data,
but each theory accounts for precisely one world of data.

hmmm.  that sounds fishy, of course, but I think that the difference is this:
so far I am only admitting to my formal arena complete datasets (languages)
and complete theories (grammars).  it is possible to make this all more
realistic from an empirical standpoint if we really want to.

j