3 Evaluation and Compilation 3.1 Evaluation 3.1.2 The Evaluation Model 22.214.171.124 Form Evaluation
126.96.36.199.2 Conses as Forms
A cons that is used as a form is called a compound form.
If the car of that compound form is a symbol,
that symbol is the name of an operator,
and the form is either a special form, a macro form,
or a function form, depending on the function binding
of the operator in the current lexical environment.
If the operator is neither a special operator
nor a macro name, it is assumed to be a function name
(even if there is no definition for such a function).
If the car of the compound form is not a symbol,
then that car must be a lambda expression,
in which case the compound form is a lambda form.
How a compound form is processed depends on whether it is
classified as a special form, a macro form,
a function form, or a lambda form.
188.8.131.52.2.1 Special Forms
184.108.40.206.2.2 Macro Forms
220.127.116.11.2.3 Function Forms
18.104.22.168.2.4 Lambda Forms