The slope would be undefined and it would be wrote as (0,0)
        
             
        
        
        
#1984 What does O'Brien say he will send them?
<u>a copy of THE BOOK </u> ✓ 
- O' Brian told them that he'd sent them a book which solely descripts the rules of the society and also the method to damage it.
descriptions of their new lives
a list of crimes against the state to commit
a list of names of people to contact
 
        
             
        
        
        
First, it signals the end of Bill and Mary's attempt at conversation, startling Mary into the present.
If the lights symbolize truth or revelation, then their sudden brightness represents the irrefutable passage of time and the impossibility of ever recovering or re-doing the past. That the lights run "the whole length of Fifth Avenue" further emphasizes the completeness of this truth; there is no way to escape the passage of time.
It's worth noting that the lights turn on right after Bill says, "You ought to see my kids" and grins. It's a surprisingly unguarded moment, and it's the only expression of genuine warmth in the story. It's possible that his and Mary's children might represent those lights, being the brilliant chains that link the past with an ever-hopeful future.