Retreat is a type of Signal. Signal is related to Left. Left is related to Escape. 
Type is related to Slip. Slip is related to Light. Light is related to Beam. Beam is a synonym of Timber. 
Retreat --IsA--> Signal <--RelatedTo--> Left <--RelatedTo--> Escape 
Type <--RelatedTo--> Slip <--RelatedTo--> Light <--RelatedTo--> Beam <--Synonym--> Timber 