@prefix pizza5: <http://example.org#> .
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .

pizza5:PizzaTopping a rdfs:Class .

pizza5:hasBase a rdf:Property .

pizza5:Pizza a rdfs:Class;
  pizza5:hasBase pizza5:PizzaBase;
  pizza5:hasTopping pizza5:PizzaTopping .

pizza5:PizzaBase a rdfs:Class .

pizza5:hasTopping a rdf:Property .