title: R: Where are formals for a function stored in memory?
body: <p>When a function has been defined but has not yet been called, do the formals that do not have default values exist? If they do, do they exist in the execution environment, or in the environment where the function definition is located, or somewhere else?</p>
  
  <p>If a function has been defined but not yet called, and a formal has been assigned a default value, does that value exist? If it does, in what environment does it exist? If the default expression evaluates to a constant, has the formal been assigned to that value, to be overwritten when the function is called if a value is supplied? If not, in what environment is that (fixed) default value located between the moment of definition and the time the function is called?</p>
  
  <p>After the function has been called and actual or default values have been assigned to the formals, passed into the body, and if necessary scoped and/or evaluated, do the formals continue to exist? If so, in what environment do they then exist?</p>