I read from A Comprehensive Grammar of English Language (Quirk, 1985) that sporadic usage of definite article "the" indicates about about location but not a specific one, but an institutionalized one. "We call this the sporadic use of the, because reference is made to an institution which may be observed recurrently at various places and times". When someone says "My sister goes to the theatre every month", with situational usage, we said that his/her sister goes to a particular theatre. But with this new sporadic usage, we can't ask which theatre his/her sister is going to because it will be inappropriate Quirk says in his book.
But now I read another part of the book, "We have already mentioned (cf. 5.33) the use of the in noun phrases with 'sporadic' definite reference, as in the radio, the theatre. In other cases, however, the sporadic use has become so institutionalized that the article is not used." This says that when the same word is used without article (zero article), it becomes quasi-locative (not indicating places, but something abstract). For example:
Be in prison = becoming a prisoner
Walk in the prison = casual visitor walking in the prison
About "Walk in the prison", the book says that the definite usage in this sentence uses cataphoric usage but "Be in prison" is in zero article usage because it is so institutionalized.
Now we got disconnected idea about sporadic usage. Sporadic usage is different from Cataphoric usage, but when it becomes so institutionalized, Zero article is incomparable to cataphoric usage, which now doesn't include the sporadic usage. So, should sporadic usage be placed in the middle of zero article usage and cataphoric usage, or in "very institutionalized" usage of zero, we can attach "the" to reduce its institutional meaning to become close to locative meaning?