For the type definition of DataSetApi.Types.ConditionOperator in componentframework.d.ts - the list of operators is missing the value 13 for 'NotNull'
I'm guessing this is a mistake because using this value correctly filters the dataset.
The current definition is:
namespace DataSetApi {
namespace Types {
/**
* Supported Condition Operator for filtering expression condition
* This is subset of full condition operators list defined in https://docs.microsoft.com/en-us/dotnet/api/microsoft.xrm.sdk.query.conditionoperator
*/
type ConditionOperator = -1 | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 8 | 12 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 22 | 23
| 25 | 26 | 27 | 28 | 29 | 33 | 34 | 37 | 38 | 49 | 70 | 75 | 76 | 77 | 78 | 79 | 87;