Assertion: pencil sharpener | /r/HasProperty | top walls of said chamber
Facets:
Source sentences:
text: A pencil-sharpener, comprising a block or casing in which is formed a chamber which is open at the top, the top walls of said chamber beingprovided with an inwardly-directed end of said arm or plate, substantially as annular flange or rim, which is provided with shown and described.