It refers to a principle in integrable systems taking the form of local equivalence transformations which appear in a variety of contexts, such as electric networks, knot theory and braid groups, and spin systems, to name just a few.
It refers to a principle in integrable systems. This is to name just a few. It is taking the form of local equivalence transformations. This is to name just a few. This form of local equivalence transformations appear in a variety of contexts and spin systems. This is such as electric networks. This is such as knot theory. This is such as braid groups.