Catalog is related to Course. Course is related to Trail. 
Grass is a type of Crop. Crop is related to Commodity. Shopping is a type of Commodity. one thing you do when you Shopping is Stop. 
Catalog <--RelatedTo--> Course <--RelatedTo--> Trail 
Grass --IsA--> Crop <--RelatedTo--> Commodity <--IsA-- Shopping --HasSubevent--> Stop 