- May 4, 2012: typos in ArXiv paper (corrected in local version).
- page 2: 1-(-1)^d also the second time in second last paragraph
- page 3: f(y) >= f(x) the second time
- second paragraph: Latex typo in reference cite{DincaMawhin}
- June 29, 2013, typos.
- Eugene Presnov pointed out some references published in the period of "an unpublished
talk by Ishida from 1990 which appeared in the
Japan journal "Forma", 1990, vol. 5(1), p.59-61 and
Speculations in Science and Technology", 1991, vol.14(1), p.68-75.
The references are added to local version.