Likely is related to Very. Very is related to Difficult. Difficult is related to Task. Task is related to Work. 
Nature is related to Discover. Discover is a synonym of Invent. 
Likely <--RelatedTo--> Very <--RelatedTo--> Difficult <--RelatedTo--> Task <--RelatedTo--> Work 
Nature <--RelatedTo--> Discover <--Synonym--> Invent 