Intelligent is a synonym of Thinking. one thing you do when you Working is Thinking. Working can cause/lead to Fatigue. Fatigue is related to Tired. 
you are likely to find Rock in/at/on Cave. 
Intelligent <--Synonym--> Thinking <--HasSubevent-- Working --Causes--> Fatigue <--RelatedTo--> Tired 
Rock --AtLocation--> Cave 