Arlington County has an extensive network of bicycle infrastructure, including 50 miles of shared-use off-street trails. These multi-use trails are generally 10 feet wide with a solid yellow line striped down the middle to separate users.
Constructive mathematics. Idea. Broadly speaking, constructive mathematics is mathematics done without the principle of excluded middle (or other principles, such as the full axiom of choice, that imply it).
1 A constructive force is a process that raises or builds up the surface features of the Earth. 2  Destructive Force. 3  A destructive force is a process that lowers or tears down the surface features of the Earth.