Premise:
"The circular Pantheon (Piazza della Rotonda) is the best-preserved monument of ancient Rome and rivals the Colosseum in its combination of quiet elegance and sheer massive power."
Hypothesis: The Colosseum is similar in size to the circular Pantheon.

yes

Premise:
"Mary Cavendish was saying in the voice of a woman desperately controlling herself: "Then you won't show it to me?" To which Mrs. Inglethorp replied: "My dear Mary, it has nothing to do with that matter.""
Hypothesis: Mary didn't speak at all.

no

Premise:
"A walk on a high wire ..."
Hypothesis: A stroll on the low wire.
no