Normal Form Simulation for McCarthy's Amb

Amb Breaks Well-Pointedness, Ground Amb Doesn't

McCarthy’s amb operator has no known denotational semantics, and its basic operational properties the context lemma, the compatibility of refinement similarity and convex bisimilarity have long been open. In this paper, we give a single example program that demonstrates the failure of each of these properties. This shows that there cannot be any well-pointed denotational semantics. However, we ...

A Normal Form for Braids

We present a seemingly new normal form for braids, where every braid is expressed using a word in a regular language on some simple alphabet of elementary braids. This normal form stems from analysing the geometric action of braid groups on curves in a punctured disk.

A Normal Form for XML

normal form for excitable media

We present a normal form for traveling waves in one-dimensional excitable media in the form of a differential delay equation. The normal form is built around the well-known saddle-node bifurcation generically present in excitable media. Finite wavelength effects are captured by a delay. The normal form describes the behavior of single pulses in a periodic domain and also the richer behavior of ...

Notes on Normal Form

A favorite parlor game of us engineers, scientists and mathematicians is to find the exact solution for a given nonlinear problem. It is generally difficult to come up with a technique to solve a given nonlinear problem exactly. A traditional analysis approach is to approximate the given nonlinear system by a first order linear system about its nominal point and hope that solution of approximat...