The CQL-to-ELM translator supports Function-style invocation of keyword-based operators, as an aspect of the way that method-style invocation is supported (and now in 1.5 fluent functions). For example:
```
define "BMI Exam Result Geater Than 40 During Measurement Period and On or Before Follow Up USS Assessment":
  Exists(["Physical Exam, Performed": "Body mass index (BMI) [Ratio]"] BMIExam
    with "Urinary Symptom Score 6 to 12 Months After Initial BPH Diagnosis" FollowUpUSSAssessment
    such that BMIExam.result > 40 'kg/m2'
      and Global.EarliestOf(BMIExam.relevantDatetime, BMIExam.relevantPeriod) during "Measurement Period"
      and Global.EarliestOf(BMIExam.relevantDatetime, BMIExam.relevantPeriod) on or before FollowUpUSSAssessment.assessementDatetime
    return Global.EarliestOf(BMIExam.relevantDatetime, BMIExam.relevantPeriod)
  )
```
Note the use of `Exists` as a function rather than the keyword-based `exists` operator.