Order comparisons between values of different types may return a boolean instead of `null`.

[Silence6666668]

Describe the bug
Order comparisons between values of different types may return a boolean instead of null.

In the minimized repro below, Apache AGE evaluates 30 > 'Rex' as true and 30 < 'Rex' as false.

On both Neo4j and Memgraph, the same expressions evaluate to null.

This suggests Apache AGE is applying a cross-type ordering for > / < comparisons where other Cypher implementations treat the comparison result as null.

How are you accessing AGE (Command line, driver, etc.)?

• PostgreSQL cypher(...) wrapper through the local Python differential-testing harness
• Reproducible directly in psql inside the Docker container

What data setup do we need to do?
No graph data is required beyond creating an empty graph:

SELECT create_graph('fuzz_graph');

What is the necessary configuration info needed?

• Plain Apache AGE Docker image was enough
• Docker image in local repro: apache/age
• AGE extension version: 1.7.0
• PostgreSQL version: 18.1
• Graph name used in repro: fuzz_graph
• No extra extensions or special configuration were required

What is the command that caused the error?

SELECT * FROM cypher('fuzz_graph', $$
  RETURN 30 > 'Rex' AS gt,
         30 < 'Rex' AS lt,
         30 = 'Rex' AS eq
$$) AS (gt agtype, lt agtype, eq agtype);

Returned result on AGE:

gt   | lt    | eq
-----+-------+------
true | false | false

Expected behavior
The equality result 30 = 'Rex' being false is fine, but the ordering comparisons should evaluate to null rather than true / false.

Expected result:

gt   | lt   | eq
-----+------+------
null | null | false

Neo4j returns:

gt   | lt   | eq
-----+------+------
null | null | false

Memgraph returns the same result.

Environment (please complete the following information):

• Version: Apache AGE 1.7.0
• PostgreSQL: 18.1
• Host OS: Windows
• Architecture: x86_64
• Deployment: Docker

Additional context
The same difference also reproduces when the values come from graph properties instead of literals:

SELECT * FROM cypher('fuzz_graph', $$
  CREATE (:Person {name:'Alice', age:30}),
         (:Dog {name:'Rex'})
$$) AS (v agtype);

SELECT * FROM cypher('fuzz_graph', $$
  MATCH (person:Person), (dog:Dog)
  WHERE person.name = 'Alice' AND dog.name = 'Rex'
  RETURN person.age > dog.name AS v
$$) AS (v agtype);

Apache AGE returns:

true

while Neo4j and Memgraph both return:

null

This issue was first found during automated Neo4j-vs-AGE differential testing in a larger query:

MATCH (person:Person)
WHERE COUNT { (person)-[:HAS_DOG]->(dog:Dog) WHERE person.age > dog.name } > 0
OPTIONAL MATCH (person)-[:HAS_DOG]->(dog:Dog)
RETURN DISTINCT person.name AS name, collect(dog.name) AS dogNames
ORDER BY name
LIMIT 2

After minimization, the same semantic difference still reproduces with the direct literal comparison above.