The Z Specification for the OBCIE Approach

Definition 1 Ontology : An ontology O is a quintuple, O = (C ,P , I ,V ,A) where C ,P , I ,V , and A are the sets of classes, properties, individuals, property values and other axioms (such as constraints) respectively. These sets are defined as follows. C = {c | c is a unary predicate} P = {p | p is a binary predicate} I = {c(i) | c ∈ C ∧ i is a ground term} V = {p(x , y) | p ∈ P ∧ x and y are ground terms ∧ (∃ c c ∈ C ∧ c(x ))} A = {a | a is an assertion}