In a restaurant, all the dishes belong to Sichuan cuisine or Cantonese cuisine. There is Sichuan cuisine in Mr. Zhang's order. Therefore, Mr. Zhang ordered no Cantonese cuisine.
The restaurant rule: you don't need to order Cantonese cuisine if you order Sichuan cuisine; but if you order Cantonese cuisine, you must also order Sichuan cuisine should be added to make the above argument true.