Zabbix | Trigger prototype | Expression | Evaluation Non Numeric

[SAFATechy]

Hi Zabbix Community

I would like to know how to create a trigger prototype, where the expression:

{Template App Foo:get.foo.ver[{$SHELLDIR},{#FOO}].last()}<>{Template App Foo:get.foo.ver[{$SHELLDIR},{#FOO}].prev()}

The evaluation of the expression is not numeric

Result:

"Cannot evaluate expression: expected numeric token at "1.1.2)<>(1.1.3)" "

Is there a way I can construct an expression that would evaluate non numeric?

Kind regards
SAFATechy

[Pato]

{Template App Foo:get.foo.ver[{$SHELLDIR},{#FOO}].diff()} ?