As of Drools 7.32.0.Final, forall patterns with "empty list" constraints combined with other constraints through || will fail to match as expected.

For example the following rule:

rule "forall with not equal"
when forall($p : Pojo(y == 1)
            Pojo(x.empty || x contains 2, z == 3, this == $p))
then
end

will not fire against following facts:

Pojo{x=[2], y=0, z=0}
Pojo{x=[], y=1, z=3}
Pojo{x=[3], y=0, z=3}
Pojo{x=[2], y=1, z=3}

We suspect a problem with the rewriting of the forall clause. It appears the clause is rewritten as:

not Pojo(y == 1, (x.empty && !(x contains 2)) || !(z == 3))

instead of the expected:

not Pojo(y == 1, (!(x.empty) && !(x contains 2)) || !(z == 3))

This is working fine when using Drools <= 7.31.0.Final.