Premise:
"First colt out of that thar breedin' was that Oro hoss."
Hypothesis: Oro horse was the first colt from that pair.

yes

Premise:
"As far as we know, the U.S. is the only country that has a mail box rule."
Hypothesis: The U.S. has a mailbox law.

it is not possible to tell

Premise:
"But too often downsizing means what it has in the Union Pacific fewer people doing more work."
Hypothesis: Downsizing in the Union Pacific leads to more people doing less work.
no