lambda expression: create a compound procedure
("double bubble"). The text (i.e. parameters and body) come
from the lambda expression; the environment is the one you
are using to evaluate the lambda expression.
Combination: "Evaluate, then apply". To
apply a compound procedure ("double bubble"):
Create a new frame [parameters].
Fill the frame [arguments].
Link the frame to make it an environment [environment].
Evaluate the body using the new environment [body].
