6051
rather more fun is book-crossing , started in the us by a software developer to encourage the release of books into the wild so they can be enjoyed by others .
 product producer: software, developer
Given options, please tell me the relationships of all the listed entity pairs.Output format is "relation1: word1, word2; relation2: word3, word4". 
Option: component whole, NA, instrument agency, member collection, cause effect, entity destination, content container, message topic, product producer, entity origin 
Text: {0} 
 Entity Pairs:  software, developer 
Answer:
 product producer: software, developer