added inform_file_processed, inform_file_retracted;
proper outer syntax setup;
more robust theory loader actions;
Sep2 = List +
consts sep :: "'a * 'a list => 'a list"
recdef sep "measure (%(a,xs). length xs)"
"sep(a, x#y#zs) = x # a # sep(a,y#zs)"
"sep(a, xs) = xs"
end