0 < ax + by + cz < 0
Embed the image to your blog in HTML, Markdown, Textile, BBCode.
Recent Referers:
  1. http://ameblo.jp/smz-chu/entry-10123476116.html
  2. http://ameblo.jp/smz-chu/
  3. http://blog.ameba.jp/ucs/entry/srventryupdateinput.do?id=...