In LL, only basic special forms and builtin functions are directly understood by the compiler. Often-used builtins that can be defined via these basic special forms and builtins are contained in the prelude which is loaded at system startup.
In the following subsections, the LL builtins will be described. If the reader is familiar with COMMON LISP, most of these subsections may be skipped (except subsection 3.2.3, which describes LL structures).
Only short definitions of the LL builtins are given. A detailed description can be found in the LISP literature [\protect\citeauthoryearSteele Jr.1984].