U.S. Patent Act
..Part II. Patentabililty of Inventions and Grant of Patents
....Chapt. 10. Patentability of Inventions
A patent may not be obtained though the invention is not identically disclosed or described as set forth in section 102 of this title [35 USCS Sect. 102], if the differences between the subject matter sought to be patented and the prior art are such that the subject matter as a whole would have been obvious at the time the invention was made to a person having ordinary skill in the art to which said subject matter pertains. Patentability shall not be negatived by the manner in which the invention was made.
Subject matter developed by another person, which qualifies as prior art only under subsection (f) or (g) of section 102 of this title [35 USCS Sect. 102(f), (g)], shall not preclude patentability under this section where the subject matter and the claimed invention were, at the time the invention was made, owned by the same person or subject to an obligation of assignment to the same person.