`TFPConstExpression`
		CreateString
		CreateInteger
		CreateDateTime
		CreateFloat
		CreateBoolean
		CreateCurrency
		Check
		NodeType
		GetNodeValue
		AsString

`TFPExprNode`
pt		CheckNodeType
pt		GetNodeValue
		Check
		InitAggregate
		UpdateAggregate
		IsAggregate
		HasAggregate
		NodeType
		NodeValue
		AsString