Assertion: blackboard eraser | /r/ObjectUse | used for several days
Facets:
value: without cleaning
type: TEMPORAL
value: in succession
type: TEMPORAL
Source sentences:
text: No. 2,249,912 in such a way that no final cleaning is required at the end of a day's use, and that the blackboard eraser provided herein can be used for several days in succession without cleaning.