Period is related to Year. Year is related to Old. Old is similar to Elderly. 
you are likely to find Worker in/at/on Shop. Commissioner is a type of Worker. Commissioner is derived from Commission. 
Period <--RelatedTo--> Year <--RelatedTo--> Old <--SimilarTo--> Elderly 
Shop <--AtLocation-- Worker <--IsA-- Commissioner --DerivedFrom--> Commission 