Temporal network point values must satisfy the constraints specified in Section 3.2 so that they are well defined. An error is raised whenever one of these constraints are not satisfied. Examples of incorrect values are as follows.

-- null values are not allowed
SELECT tnpoint 'NULL@2001-01-01 08:05:00';
SELECT tnpoint 'Point(0 0)@NULL';
-- base type is not a network point
SELECT tnpoint 'Point(0 0)@2001-01-01 08:05:00';
-- multiple routes in a sequence
SELECT tnpoint '[Npoint(1, 0.2)@2001-01-01 09:00:00, Npoint(2, 0.2)@2001-01-01 09:05:00)';