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).
Definition of theoretical for English Language Learners. : 1  relating to what is possible or imagined rather than to what is known to be true or real. : 2  relating to the general principles or ideas of a subject rather than the practical uses of those ideas.