Specify the structure of a service contract, as defined below, using extended BNF notation.

A service contract has three sections. In the first section, a maximum of three

services are listed. Each service has a name, a parameter list, date when the service is to

be provided, and its cost. In the second section, one legal constraint pertaining to each

of the services is stated. A constraint names a service and assigns a legal code $($maximum

four digits$)$ to it$.$ The third section lists the location $($address$)$ where each service

included in the contract is to be provided.