Macros implement syntax and semantics. Arbitrary complex syntax. Check out the complex syntax for DEFGENERIC, DEFCLASS, DEFSTRUCT, defpackage ... LOOP The synt

Macros implement syntax and semantics. Arbitrary complex syntax. Check out the complex syntax for DEFGENERIC, DEFCLASS, DEFSTRUCT, defpackage ... LOOP The syntax for DEFUN in Common Lisp: defun function-name lambda-list [[declaration* | documentation]] form* The syntax for lambda-list then is: lambda-list::= (var* [&optional {var | (var [init-form [supplied-p-parameter]])}*] [&rest var] [&key {var | ({var | (keyword-name var)} [init-form [supplied-p-parameter]])}* [&allow-other-keys]] [&aux {var | (var [init-form])}*]) Lisp syntax is not atom | '(' atom* ')'. It's much more complex. And so on. Every Lisp has arbitrary complex syntax due to macros and special operators.