ENTER-BOOT-STRAP-MODE.html -- ACL2 Version 6.3

## ENTER-BOOT-STRAP-MODE

The first millisecond of the Big Bang

    Major Section:  MISCELLANEOUS

ACL2 functions, e.g., `if`, that show `enter-boot-strap-mode` as their defining command are in fact primitives. It is impossible for the system to display defining axioms about these symbols.

`Enter-boot-strap-mode` is a Common Lisp function but not an ACL2 function. It magically creates from `nil` an ACL2 property list world that lets us start the boot-strapping process. That is, once `enter-boot-strap-mode` has created its world, it is possible to process the `defconst`s, `defun`s, and `defaxiom`s, necessary to bring up the rest of the system. Before that world is created, the attempt by ACL2 even to translate a `defun` form, say, would produce an error because `defun` is undefined.

Several ACL2 functions show `enter-boot-strap-mode` as their defining command. Among them are `if`, `cons`, `car`, and `cdr`. These functions are characterized by axioms rather than definitional equations -- axioms that in most cases are built into our code and hence do not have any explicit representation among the rules and formulas in the system.