The And rule says that an and form is evaluated by evaluating each argument in turn. If all of the arguments evaluate to true, the form has the value of the last argument. The Or rule says that an or form is evaluated by evaluating each argument in urn. The results of evaluating forms are values. We name forms and create procedures.
Decisions choose among alternatives using Boolean values.
The Official Rules are an algorithm for evaluating Scheme forms. 2 - but done in Ch. Prompting is displaying some text to ask for input. A format string controls how printed values appear. A first-class value is one that can be passed as an argument, returned as a result, and used as the value of variables.