LEM

Definitions

1. Originally Lunar Excursion Module, latterly Lunar Module.
   US
2. A surname.
3. Clipping of Leamington Spa.
   abbreviation, alt-of, clipping, informal
4. Law of excluded middle.

Equivalents

Examples

“What constructive mathematicians know⟳ is that there are mathematical universes in which sets are like⟳ topological spaces and properties are like⟳ open⟳ sets. In fact, these universes are well-known to classical mathematicians (they are called toposes), but they look⟳ at them from “the outside”. When we consider⟳ what mathematicians who live⟳ in such a universe see⟳, we discover⟳ many fascinating kinds of mathematics, which tend⟳ to be constructive. The universe of classical mathematics is special because in it all sets are like⟳ discrete topological spaces. In fact, one way of understanding LEM is “all spaces/sets are discrete”. Is this really such a smart thing to assume⟳? If for no other reason⟳, LEM should be abandoned because it is quite customary to consider⟳ “continuous” and “discrete” domains in applications in computer science and physics. So what gives mathematicians the idea that all domains are discrete?”

“Went down to Lem the other day but the weather was abysmal.”

CEFR level