@prefix : <http://example.org/ns#> .
@prefix xsd:        <http://www.w3.org/2001/XMLSchema#> .

# These object values are true by the boolean effective value rule.
:x1 :p    1 .
:x2 :p    "foo" .
:x3 :p    "0.01"^^xsd:double .
:x4 :p    "true"^^xsd:boolean .

# These are false
:y1 :p    0 .
:y2 :p    "0.0"^^xsd:double .
:y3 :p    "" .
:y4 :p    "false"^^xsd:boolean .

# Optionals
:x1 :q    "true"^^xsd:boolean .
:x2 :q    "false"^^xsd:boolean .
:x3 :q    "foo"^^:unknown .