Cream is related to Shake. Shake is related to Stir. Electricity is a type of Stir. 
Access is related to Memory. Memory is related to Unit. Troop is a type of Unit. 
Cream <--RelatedTo--> Shake <--RelatedTo--> Stir <--IsA-- Electricity 
Access <--RelatedTo--> Memory <--RelatedTo--> Unit <--IsA-- Troop 