SNOMED Documentation Search
The formal syntax for SNOMED CT expression templates (v1) is shown below. This syntax is derived by combining:
As explained in 6. SNOMED CT Language Templates, references to the Template Syntax are also added into the Compositional Grammar rules to enable slots to be included within an expression template. Please note that rules that appear in both Compositional Grammar and the Expression Constraint Language (e.g. 'conceptId and term') have one of the lines commented out ) are removed from the Expression Constraint Language (by commenting out) to avoid duplication.
; Compositional Grammar v2.3.1 with template hooksslot references (in blue)
expressionTemplate = ws [ (definitionStatus / tokenReplacementSlot) ws] subExpression ws
subExpression = focusConcept [ws ":" ws refinement]
definitionStatus = equivalentTo / subtypeOf
equivalentTo = "==="
subtypeOf = "<<<"
focusConcept = [templateInformationSlot ws] conceptReference *(ws "+" ws [templateInformationSlot ws] conceptReference)
conceptReference = conceptReplacementSlot / expressionReplacementSlot / ( conceptId [ws "|" ws term ws "|"] )
conceptId = sctId
term = nonwsNonPipe *( *SP nonwsNonPipe )
refinement = (attributeSet / attributeGroup) *( ws ["," ws] attributeGroup )
attributeGroup = [ templateInformationSlot ws ] "{" ws attributeSet ws "}"
attributeSet = attribute *(ws "," ws attribute)
attribute = [ templateInformationSlot ws ] attributeName ws "=" ws attributeValue
attributeName = conceptReference
attributeValue = expressionValue / QM stringValue QM / "#" numericValue / concreteValueReplacementSlot
expressionValue = conceptReference / "(" ws subExpression ws ")"
stringValue = 1*(anyNonEscapedChar / escapedChar)
numericValue = ["-"/"+"] (decimalValue / integerValue)
integerValue = digitNonZero *digit / zero
decimalValue = integerValue "." 1*digit
sctId = digitNonZero 5*17( digit )
ws = *( SP / HTAB / CR / LF ) ; optional white space
SP = %x20 ; space
HTAB = %x09 ; tab
CR = %x0D ; carriage return
LF = %x0A ; line feed
QM = %x22 ; quotation mark
BS = %x5C ; back slash
digit = %x30-39
zero = %x30
digitNonZero = %x31-39
nonwsNonPipe = %x21-7B / %x7D-7E / UTF8-2 / UTF8-3 / UTF8-4
anyNonEscapedChar = HTAB / CR / LF / %x20-21 / %x23-5B / %x5D-7E / UTF8-2 / UTF8-3 / UTF8-4
escapedChar = BS QM / BS BS
UTF8-2 = %xC2-DF UTF8-tail
UTF8-3 = %xE0 %xA0-BF UTF8-tail / %xE1-EC 2( UTF8-tail ) / %xED %x80-9F UTF8-tail / %xEE-EF 2( UTF8-tail )
UTF8-4 = %xF0 %x90-BF 2( UTF8-tail ) / %xF1-F3 3( UTF8-tail ) / %xF4 %x80-8F 2( UTF8-tail )
UTF8-tail = %x80-BF
; Template Syntax v1
templateSlot = templateReplacementSlot / templateInformationSlot
templateReplacementSlot = conceptReplacementSlot / expressionReplacementSlot / tokenReplacementSlot / concreteValueReplacementSlot
conceptReplacementSlot = "[[" ws "+" ws "id" ws [ "(" ws expressionConstraint ws ")" ws] [slotName ws] "]]"
expressionReplacementSlot = "[[" ws "+" ws ["scg" ws] [ "(" ws expressionConstraint ws ")" ws] [slotName ws] "]]"
tokenReplacementSlot = "[[" ws "+" ws "tok" ws [ "(" ws slotTokenSet ws ")" ws] [slotName ws] "]]"
concreteValueReplacementSlot = stringReplacementSlot / integerReplacementSlot / decimalReplacementSlot
stringReplacementSlot = "[[" ws "+" ws "str" ws [ "(" ws slotStringSet ws ")" ws] [slotName ws] "]]"
integerReplacementSlot = "[[" ws "+" ws "int" ws [ "(" ws slotIntegerSet ws ")" ws] [slotName ws] "]]"
decimalReplacementSlot = "[[" ws "+" ws "dec" ws [ "(" ws slotDecimalSet ws ")" ws] [slotName ws] "]]"
slotTokenSet = slotToken *(mws slotToken)
slotStringSet = slotString *(mws slotString)
slotIntegerSet = ( "#" integerValue / slotIntegerRange) *(mws ("#" integerValue / slotIntegerRange))
slotDecimalSet = ( "#" decimalValue / slotDecimalRange) *(mws ("#" decimalValue / slotDecimalRange))
slotIntegerRange = ( slotIntegerMinimum to [ slotIntegerMaximum ] ) / ( to slotIntegerMaximum )
slotIntegerMinimum = [ exclusiveMinimum ] "#" integerValue
slotIntegerMaximum = [ exclusiveMaximum ] "#" integerValue
slotDecimalRange = ( slotDecimalMinimum to [ slotDecimalMaximum ] ) / ( to slotDecimalMaximum )
slotDecimalMinimum = [ exclusiveMinimum ] "#" DecimalValue
slotDecimalMaximum = [ exclusiveMaximum ] "#" DecimalValue
exclusiveMinimum = ">"
exclusiveMaximum = "<"
slotName = "@" (nonQuoteStringValue / slotString)
slotToken = definitionStatus / memberOf / constraintOperator / conjunction / disjunction / exclusion / reverseFlag / expressionComparisonOperator / numericComparisonOperator / stringComparisonOperator
slotString = QM stringValue QM
nonQuoteStringValue = *(%x21 / %x23-26 / %x28-3F / %x41-5A / %x5C / %x5E-7E) ; string with no ws, quotes, at or square brackets
templateInformationSlot = "[[" ws slotInformation ws "]]"
slotInformation = [cardinality ws] [slotName ws]
; Expression Constraint Language v1.3 - Note that some rules are commented out because they are repeated in the Compositional Grammar rules above.
expressionConstraint = ws ( refinedExpressionConstraint / compoundExpressionConstraint / dottedExpressionConstraint / subExpressionConstraint ) ws
refinedExpressionConstraint = subExpressionConstraint ws ":" ws eclRefinement
compoundExpressionConstraint = conjunctionExpressionConstraint / disjunctionExpressionConstraint / exclusionExpressionConstraint
conjunctionExpressionConstraint = subExpressionConstraint 1*(ws conjunction ws subExpressionConstraint)
disjunctionExpressionConstraint = subExpressionConstraint 1*(ws disjunction ws subExpressionConstraint)
exclusionExpressionConstraint = subExpressionConstraint ws exclusion ws subExpressionConstraint
dottedExpressionConstraint = subExpressionConstraint 1*(ws dottedExpressionAttribute)
dottedExpressionAttribute = dot ws [constraintOperator ws] eclAttributeName
subExpressionConstraint = [constraintOperator ws] [memberOf ws] (eclFocusConcept / "(" ws expressionConstraint ws ")")
eclFocusConcept = eclConceptReference / wildCard
dot = "."
memberOf = "^"
eclConceptReference = conceptId [ws "|" ws term ws "|"]
; conceptId = sctId
; term = 1*nonwsNonPipe *( 1*SP 1*nonwsNonPipe )
wildCard = "*"
constraintOperator = childOf / descendantOrSelfOf / descendantOf / parentOf / ancestorOrSelfOf / ancestorOf
descendantOf = "<"
descendantOrSelfOf = "<<"
childOf = "<!"
ancestorOf = ">"
ancestorOrSelfOf = ">>"
parentOf = ">!"
conjunction = (("a"/"A") ("n"/"N") ("d"/"D") mws) / ","
disjunction = ("o"/"O") ("r"/"R") mws
exclusion = ("m"/"M") ("i"/"I") ("n"/"N") ("u"/"U") ("s"/"S") mws
eclRefinement = subRefinement ws [conjunctionRefinementSet / disjunctionRefinementSet]
conjunctionRefinementSet = 1*(ws conjunction ws subRefinement)
disjunctionRefinementSet = 1*(ws disjunction ws subRefinement)
subRefinement = eclAttributeSet / eclAttributeGroup / "(" ws eclRefinement ws ")"
eclAttributeSet = subAttributeSet ws [conjunctionAttributeSet / disjunctionAttributeSet]
conjunctionAttributeSet = 1*(ws conjunction ws subAttributeSet)
disjunctionAttributeSet = 1*(ws disjunction ws subAttributeSet)
subAttributeSet = eclAttribute / "(" ws eclAttributeSet ws ")"
eclAttributeGroup = ["[" cardinality "]" ws] "{" ws eclAttributeSet ws "}"
eclAttribute = ["[" cardinality "]" ws] [reverseFlag ws] eclAttributeName ws (expressionComparisonOperator ws subExpressionConstraint / numericComparisonOperator ws "#" numericValue / stringComparisonOperator ws QM stringValue QM)
cardinality = minValue to maxValue
minValue = nonNegativeIntegerValue
to = ".."
maxValue = nonNegativeIntegerValue / many
many = "*"
reverseFlag = "R"
eclAttributeName = subExpressionConstraint
expressionComparisonOperator = "=" / "!="
numericComparisonOperator = "=" / "!=" / "<=" / "<" / ">=" / ">"
stringComparisonOperator = "=" / "!="
; numericValue = ["-"/"+"] (decimalValue / integerValue)
; stringValue = 1*(anyNonEscapedChar / escapedChar)
; integerValue = digitNonZero *digit / zero
; decimalValue = integerValue "." 1*digit
nonNegativeIntegerValue = (digitNonZero *digit ) / zero
; sctId = digitNonZero 5*17( digit )
; ws = *( SP / HTAB / CR / LF / comment ) ; optional white space
mws = 1*( SP / HTAB / CR / LF / comment ) ; mandatory white space
comment = "/*" *(nonStarChar / starWithNonFSlash) "*/"
nonStarChar = SP / HTAB / CR / LF / %x21-29 / %x2B-7E /UTF8-2 / UTF8-3 / UTF8-4
starWithNonFSlash = %x2A nonFSlash
nonFSlash = SP / HTAB / CR / LF / %x21-2E / %x30-7E /UTF8-2 / UTF8-3 / UTF8-4
; SP = %x20 ; space
; HTAB = %x09 ; tab
; CR = %x0D ; carriage return
; LF = %x0A ; line feed
; QM = %x22 ; quotation mark
; BS = %x5C ; back slash
; digit = %x30-39
; zero = %x30
; digitNonZero = %x31-39
; nonwsNonPipe = %x21-7B / %x7D-7E / UTF8-2 / UTF8-3 / UTF8-4
; anyNonEscapedChar = SP / HTAB / CR / LF / %x20-21 / %x23-5B / %x5D-7E / UTF8-2 / UTF8-3 / UTF8-4
; escapedChar = BS QM / BS BS
; UTF8-2 = %xC2-DF UTF8-tail
; UTF8-3 = %xE0 %xA0-BF UTF8-tail / %xE1-EC 2( UTF8-tail ) / %xED %x80-9F UTF8-tail / %xEE-EF 2( UTF8-tail )
; UTF8-4 = %xF0 %x90-BF 2( UTF8-tail ) / %xF1-F3 3( UTF8-tail ) / %xF4 %x80-8F 2( UTF8-tail )
; UTF8-tail = %x80-BF
...