Modeling Subclass (or Subtype) Constraints in an Entity-Relationship Diagram Scenario description

Can someone help me out on how to model the situation that follows:


There is a superclass (or supertype) called PRODUCTS, which has the subclasses (or subtypes) named FOOD and SHOES.
There exists another superclass denominated CUSTOMERS, with the subclasses denominated SHOE STORE and GROCERY STORE.
I need to represent some rules that indicate that: 


FOOD can only be delivered to GROCERY STORES.
SHOES can exclusively be distributed to SHOE STORES.



Tentative diagrams

I have tried the two diagrams shown bellow:



Diagrams considerations

Top diagram

I really do not like the duplication of (a) the same entity type, i.e., ORDERS, and (b) the relationships around it.

Bottom diagram 

I am pretty sure this not the proper notation. Should I instead create the relationship on the superclass level and make a note that the restrictions will be implemented at the programming level?
I think you can make an Orders entity that is a relationship between Products and Customers. The Orders would have subclasses FoodOrders and ShoeOrders, which respectively would be the relationships between the subclasses of Food - GroceryStores and Shoes - ShoeStores.

                                            ┌───────────┐
                                            │ Employees │
                                            └─────┬─────┘
                                                  │
                                                  │
      ┌──────────┐               ┌────────┐       │       ┌───────────┐
      │ Products ├─── contain ───┤ Orders ├─── deliver ───┤ Customers │
      └────┬─────┘               └────┬───┘               └─────┬─────┘
           │                          │                         │
           │                          │                         │
          isA                        isA                       isA
          │ │                        │ │                       │ │
     ┌────┘ └────┐             ┌─────┘ └─────┐            ┌────┘ └────┐
     │           │             │             │            │           │
 ┌───┴──┐    ┌───┴───┐         │             │    ┌───────┴───────┐   │
 │ Food │    │ Shoes │         │             │    │ GroceryStores │   │
 └───┬──┘    └───┬───┘         │             │    └───────┬───────┘   │
     │           │       ┌─────┴──────┐      │            │     ┌─────┴──────┐
     └───────────│───────┤ FoodOrders ├──────│────────────┘     │ ShoeStores │
                 │       └────────────┘      │                  └─────┬──────┘
                 │                     ┌─────┴──────┐                 │
                 └─────────────────────┤ ShoeOrders ├─────────────────┘
                                       └────────────┘