Definition 4.3.1 We identify the static scope of a cost center using ??[e] which labels e with its statically enclosing cost center cc and labels all subexpressions of e with their statically enclosing cost center.
(1) Local transformations within the static scope of a cost center do not move cost from one cost center to another (Section 5.1).
For example, consider an application of the [Lambda]-of-let transformation within the static scope of some cost center cc.
These ideas correspond directly with our notions of static scope, "current cost center," and subsumed top-level functions.
An important point in name control is whether static scope (also called lexical scope) or dynamic scope is used to locate names that are not local to a block or procedure.
Static scope binds names to declarations based on the static structure of the program; dynamic scope binds names to declarations at run-time.
Use of dynamic scope instead of static scope leads to programs that are easier to understand.