Expedition is related to Long. Long is related to Rail. Rail is related to Metal. 
Commission is a type of Command. Command is related to Rule. Rule is related to Head. Head is a type of Formation. 
Expedition <--RelatedTo--> Long <--RelatedTo--> Rail <--RelatedTo--> Metal 
Commission --IsA--> Command <--RelatedTo--> Rule <--RelatedTo--> Head --IsA--> Formation 