How can I check in Dialogflow CX if the value of parameter_A appears in parameter_B?

Question

I have two parameters.

Parameter_A has the value: "a" and parameter_B has the value: ["a", "b", "c"].

Now I want to check via 'Condition' if parameter_a occurs in parameter_b.

I tried: $session.params.b : $session.params.a

Also I tried: $sys.func.Contain($session.params.b, $session.params.a)

Answer 1

Ok, solved it.

I had to add = true

$sys.func.CONTAIN($session.params.b, $session.params.a) = true works