Impossible is related to Difficult. Difficult is related to Complicated. World can be Complicated. World is related to Web. 
Article is part of Document. Article is a type of Artifact. Icon is a type of Artifact. 
Impossible <--RelatedTo--> Difficult <--RelatedTo--> Complicated <--HasProperty-- World <--RelatedTo--> Web 
Document <--PartOf-- Article --IsA--> Artifact <--IsA-- Icon 