Assertion: royalty trust | /r/CapableOf | involve mine
Facets:
value: usually
type: DEGREE
Source sentences:
text: Additionally, royalty trusts in the United States and Canada usually involve oil and gas fields or mines which are at or past their production peak, and will gradually decline in output as well as revenue; however, the infrastructure to develop them has already been built, so that an investor can expect a reasonably steady income stream.