Premise:
"At the heart of Hinduism is belief in a life essence and a common soul, atman, which all living things share, and in reincarnation, the soul's rebirth after death in another form."
Hypothesis: Belief that life essence and common soul, atman, exists, as well as reincarnation, are at the heart of Hinduism.

yes

Premise:
"He's my cousin, Drew returned."
Hypothesis: Drew has a cousin.

yes

Premise:
"Suppose a potential competitor needed a critical mass in order to begin operations."
Hypothesis: A potential competitor may need a critical mass in order to start operating.
yes