Sleep is related to Action. Choice is a type of Action. 
you are likely to find Mouse in/at/on Outside. you are likely to find Mouse in/at/on Snake. you are likely to find Snake in/at/on Mountain. Mountain is related to Goat. 
Sleep <--RelatedTo--> Action <--IsA-- Choice 
Outside <--AtLocation-- Mouse --AtLocation--> Snake --AtLocation--> Mountain <--RelatedTo--> Goat 