<owl:AnnotationProperty rdf:about="http://purl.obolibrary.org/obo/IAO_0000231">
    <rdfs:label xml:lang="en">has obsolescence reason</rdfs:label>
    <obo:IAO_0000117 xml:lang="en">PERSON:Alan Ruttenberg</obo:IAO_0000117>
    <obo:IAO_0000117 xml:lang="en">PERSON:Melanie Courtot</obo:IAO_0000117>
    <obo:IAO_0000115 xml:lang="en">Relates an annotation property to an obsolescence reason. The values of obsolescence reasons come from a list of predefined terms, instances of the class obsolescence reason specification.</obo:IAO_0000115>
    <obo:IAO_0000111 xml:lang="en">has obsolescence reason</obo:IAO_0000111>
</owl:AnnotationProperty>

(defoproperty hasTopping
  :super hasComponent
  :range PizzaTopping
  :domain Pizza)

(defpartition Hydrophobicity
  [Hydrophobic Hydrophillic]
  :comment "Part of the Hydrophobicity value partition"
  :super PhysicoChemicalProperty
  :domain AminoAcid)

(defaminoacids
  [Alanine       Ala A] [Neutral  Hydrophobic NonPolar Aliphatic Tiny]
  [Arginine      Arg R] [Positive Hydrophilic Polar    Aliphatic Large]
  [Asparagine    Asn N] [Neutral  Hydrophilic Polar    Aliphatic Small]
  [Aspartate     Asp D] [Negative Hydrophilic Polar    Aliphatic Small]
  [Cysteine      Cys C] [Neutral  Hydrophobic Polar    Aliphatic Small]
  [Glutamate     Glu E] [Negative Hydrophilic Polar    Aliphatic Small]
  [Glutamine     Gln Q] [Neutral  Hydrophilic Polar    Aliphatic Large]
  [Glycine       Gly G] [Neutral  Hydrophobic NonPolar Aliphatic Tiny])

;; \begin{tawny}
(defclass MargheritaPizza
  :super
  Pizza
  (owl-some hasTopping MozzarellaTopping)
  (owl-some hasTopping TomatoTopping)
  (only hasTopping (owl-or MozzarellaTopping TomatoTopping)))
;; \end{tawny}

;; \begin{itemize}
;; \item |only| a new function which returns a \emph{universal restriction}
;; \item |owl-or| which returns a \emph{union restriction}
;; \end{itemize}