veggie pizza better definition

pizza.ttl

@prefix : <http://example.org/pizza#> .
@prefix owl: <http://www.w3.org/2002/07/owl#> .
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .

:hasTopping a owl:ObjectProperty .

:VegetablePizza a owl:Class ;
    owl:equivalentClass [
        a owl:Class ;
        owl:intersectionOf (
            :Pizza
            [ a owl:Restriction ;
              owl:onProperty :hasTopping ;
              owl:someValuesFrom :VegetableTopping
            ]
            [ a owl:Restriction ;
              owl:onProperty :hasTopping ;
              owl:allValuesFrom :VegetableTopping
            ]
        )
    ] .

# not veggie pizza unless you turn off the (only :VegetableTopping) condition
:isItVeggie :hasTopping :pepper5 ;
  a owl:NamedIndividual, :Pizza .

:fredPie a :VegetablePizza ;
# :hasTopping [ a :VegetableTopping ] ;
:hasTopping :topping99, :topping55 ;  # these have to be veggie toppings
  a owl:NamedIndividual .

:pepper5 a :VegetableTopping .

# this is also veggie pizza since it has some and only veggie toppings
:pie5 a owl:NamedIndividual, :Pizza ;
    :hasTopping :pepper5 ;
    rdf:type [
        a owl:Restriction ;
        owl:onProperty :hasTopping ;
        owl:allValuesFrom [ 
            owl:oneOf ( :pepper5 ) 
        ]
    ] .