application rule
to apply a procedure
- create a new frame for its arguments
- bind the arguments to their values in this frame
- make the new frame point to the procedure’s environment
- now evaluate the body in the environment that starts with the new frame
example
- consider application (down 1)
- create a new frame that binds i to 1
- lin k to the top-level env E1 (because this is the environment in which down was created)
- now evaluate the body in this environment E2
- x refers to the x in the frame that is the sole frame of environment E1