@prefix math: <http://www.w3.org/2000/10/swap/math#>.
@prefix : <http://example.org/#>.

10 a :NaturalNumber.

# All x : (X a EvenNumber) OR (X a OddNumber)
true => ($ {
    ?x a :OddNumber.
} {
    ?x a :EvenNumber.
} $).

# All x,y : (X a NaturalNumber) ->  (y = x-1, y > 0 a NaturalNumber)
{
    ?x a :NaturalNumber.
    (?x -1) math:sum ?y.
    ?y math:greaterThan 0.
} => {
    ?y a :NaturalNumber.
}.

# All x : (X a NaturalNumber) -> ( x : 2 = 0 , not(X a OddNumber) )
{
    ?x a :NaturalNumber.
    (?x 2) math:remainder 0.
} => {
    {
        ?x a :OddNumber.
    } => ($ $).
}.

# query
{
    ?x a ?y.
} =^ {
    ?x a ?y.
}.
