pSPARQL: A Querying Language for Probabilistic RDF Data

Table 1

Truth tables for the three-valued semantics.

(a)

true	true	true	true
true	false	false	true
true	error	error	true
false	true	false	true
false	false	false	false
false	error	false	error
error	true	error	true
error	false	false	error
error	error	error	error

(b)

true	false
false	true
error	error