Rescue is a synonym of Release. Release is a type of Device. Device is a different concept from Machine. Machine is related to General. 
Recession is a synonym of Return. Return is related to Enter. Enter is a different concept from Exit. 
Rescue <--Synonym--> Release --IsA--> Device <--DistinctFrom--> Machine <--RelatedTo--> General 
Recession <--Synonym--> Return <--RelatedTo--> Enter <--DistinctFrom--> Exit 