The equation

THE EQUATION
 
This can be found on page 336 of Narrow Roads of Gene Land by W. D. Hamilton
 
ISBN 0-7167-4530-5 the 96 Paperback edition
 
The fragment of equation on our heroine's handbag
 
 
 
Represents the criterion for the positive selection of altruism within a gene pool.
 
 
AN ANTIDOTE