San Francisco Health Care Security Ordinance & its intersection with the Health Care Accountability Ordinance Joannie C. Chang Office of Labor Standards Enforcement City & County of San Francisco January 2009.
In geometry, a torus (plural tori) is a surface of revolution generated by revolving a circle in three-dimensional space about an axis coplanar with the circle.he flat torus is a torus with the metric inherited from its representation as the quotient, R 2 / L, where L is a discrete subgroup of R 2 isomorphic to Z 2. This gives the quotient the structure of a Riemannian manifold.
A torus is a surface formed by revolving a circle about a line. Often, tori (the plural of torus) are doughnut shaped, as in the main image here. It is formed by revolving a circle about the z-axis. It can also be described as a ring-shaped surface with a hole. torus with one hole is simply referred to as the torus. A torus with two holes is called the 2-torus or the double torus, one with three holes is the 3-torus or triple torus. A torus with holes is the-torus. Mathematically, we can describe tori using several different equations.