Yes. For instance, there are numerous problems in mathematics that are undecidable (cannot be proven true or false) when the axioms of set theory used are the Zermelo-Fraenkel axioms.
Perhaps if you would take a break from your rigorous study of Mao Zedong thought you would come to understand humor and sarcasm. The point is that pornography is hardly a "foreign" influence on China. they've been making it just as long as anyone else has.