ORA-DM-A-LANGUAGE

*
Data Model, Section 1. Introduction* Second para, last sentence:
"A language is closed ... if the value of every expression in a 
language...".
The second occurrence of "language" is meant to refer back to the first 
occurrence.
Suggested solution: change the second "a language" to either "the 
language" or "that language".
Alternatively, you can replace the first occurrence of "a language" by 
"a language L" and replace the second occurrence by "L".