> Patents are awarded by first to invent not first to file. The default value for date-of-invention is date-of-filing. An inventor who wants to establish an ea

> Patents are awarded by first to invent not first to file. The default value for date-of-invention is date-of-filing. An inventor who wants to establish an earlier date-of-invention has the burden of proof (and must provide corroborating evidence such as a dated- and witnessed lab notebook, because it's too easy for an inventor to "misremember"). (Yes, we're talking current U.S. law here; most other countries are indeed first-to-file.) Additional reading: http://en.wikipedia.org/wiki/First_to_file_and_first_to_invent http://en.wikipedia.org/wiki/First_to_file_and_first_to_inve...