User input is on lines with the :-prompt; CASSIE's output is on the lines that follow.
: Young Lucy petted a yellow dog
I understand that young Lucy petted a yellow dog 
: What is yellow
a dog is yellow 
: Dogs are animals
I understand that dogs are animals 
: Who petted an animal
young Lucy petted a yellow dog 
: Lucy is clever
I understand that young Lucy is clever 
: Lucy is a girl
I understand that clever young Lucy is a girl 
: Girls are people
I understand that girls are people 
: What was petted by a person
a yellow dog was petted by clever young Lucy 
: The dog is named Rover
I understand that Rover is a yellow dog 
: What was petted by a person
yellow Rover was petted by clever young Lucy 
: For every d
  if d is a dog
  then there is a b
  such that b is a boy
  and b owns d
I understand that for every d,
if d is a dog
then there exists a b
such that b is a boy 
and b owns d 
: The boy is named John
I understand that John is a boy 
: Who owns Rover
John owns yellow Rover 
: John believes that Lucy is rich
I understand that John believes that Lucy is rich 
: Who is rich
I don't know. 
: Who is clever
young Lucy is clever 
: John believes that Lucy is old
I understand that John believes that rich Lucy is old 
: Boys are people
I understand that boys are people 
: Dogs are pets
I understand that dogs are pets 
: For every p and d
  if p is a person
     and d is a pet
  then p loves d
I understand that
for every d and p,
if p is a person 
and d is a pet 
then p loves d 
: Who loves a pet
clever young Lucy loves yellow Rover 
and 
John loves yellow Rover 
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