Support for AQL MATCHES and TERMINOOLGY in EhrBase?

I have been trying to run a SNOMED query via FHIR interface to Ontoserver, based on this example

select  e/ehr_id/value, 
o/data[at0001]/events[at0002]/data[at0003]/items[at0004]/value/defining_code/code_string from EHR e 
contains COMPOSITION a [openEHR-EHR-COMPOSITION.externalterm.v0] 
contains OBSERVATION o [openEHR-EHR-OBSERVATION.externalterm.v0]
WHERE o/data[at0001]/events[at0002]/data[at0003]/items[at0004]/value/defining_code matches [TERMINOLOGY('expand', 'hl7.org/fhir/r4', 'url=http://hl7.org/fhir/ValueSet/condition-code')]

based on this AQL sample

WHERE
    e/value/defining_code/code_string matches TERMINOLOGY('expand', 'hl7.org/fhir/r4', 'url=http://snomed.info/sct?fhir_vs=isa/50697003')

but am getting an error

{
    "error": "Bad Request",
    "message": "Could not process query/stored-query, reason: org.antlr.v4.runtime.misc.ParseCancellationException: AQL Parse exception: line 4: char 91 no viable alternative at input 'o/data[at0001]/events[at0002]/data[at0003]/items[at0004]/value/defining_codematches['"
}

It looks to me as if the MATCHES clause is not supported. We know the FHIR Valueset is correct and avaiable.

Am I doing something wrong or should this be reported?

@luis_marco @stefanspiska