Radiation is a type of Starting. Starting is a different concept from End. End is related to Beginning. 
Steel is related to Structure. Structure is related to Shape. Solid is a type of Shape. 
Radiation --IsA--> Starting <--DistinctFrom--> End <--RelatedTo--> Beginning 
Steel <--RelatedTo--> Structure <--RelatedTo--> Shape <--IsA-- Solid 