XtGetSelectionValueIncremental (3x)  - obtain selection values
XtGetSelectionValuesIncremental [XtGetSelectionValueIncremental] (3x)  - obtain selection values
XtOwnSelectionIncremental [XtOwnSelection] (3x)  - set selection owner
combinediff          (1)  - create a cumulative unified patch from two incremental patches
splitdiff            (1)  - separate out incremental patches