Trying to convert the following statement to CQL. And received an error msg “Interval type expected” for the last line in the definition 3 below (highlighted line).

QDM version -
• Denominator Exclusions =
o OR: "Procedure, Performed: Spinal Fusion" starts before start of "Occurrence A of Procedure, Performed: Total Hip, Total Knee Replacement"
CQL version –
1. Create a function for “Occurrence A of Procedure, Performed: Total Hip, Total Knee Replacement", which is re-used from IPP to Numerator.

define function "Total Hip Total Knee Procedure"(Encounter "Encounter, Performed" ):
["Procedure, Performed": "Total Hip, Total Knee Replacement"] TotalHipTotalKneeProcedures
with Encounter QualifyingEncounters
such that TotalHipTotalKneeProcedures.relevantPeriod starts during Interval[start of QualifyingEncounters.relevantPeriod - 48 hours, end of QualifyingEncounters.relevantPeriod]

2. define "Encounters Ages Greater Than Or Equal To 18":
Global."Inpatient Encounter" InpatientEncounter
with ["Patient Characteristic Birthdate"] BirthDate
such that Global."CalendarAgeInYearsAt"(BirthDate.birthDatetime, start of InpatientEncounter.relevantPeriod)>= 18

3. define "History of Spinal Fusion"
"Encounters Ages Greater Than Or Equal To 18" QualifyingEncounters
let Procedure: "Total Hip Total Knee Procedure"(QualifyingEncounters)
with ["Procedure, Performed": "Spinal Fusion"] HistoryOfSpinalFusion
such that Procedure.ordinality in "Principal"
and HistoryOfSpinalFusion.relevantPeriod starts before start of Procedure.relevantPeriod