Premise:
"Memorandum to Jim DeMocker, Office of Air and Radiation, Office of Policy Analysis and Review, US Environmental Protection Agency, June 27."
Hypothesis: Jim DeMocker was part of the US Environmental Protection Agency on June 27.

yes

Premise:
"The nearby Cite de la Musique, on the other side of the canal, has a new concert hall, the ultra-modern buildings of the Conservatoire National (music academy), and an impressively large rock venue, the Zenith."
Hypothesis: The nearby city has a couple of music venues.

it is not possible to tell

Premise:
"The Merchant followed along the line of his thoughts."
Hypothesis: The Merchant kept talking about the same thing.
yes