This is why, by default on 32-bit architectures, fixnums in GNU Emacs are 30 bits: http://stackoverflow.com/questions/106597/why-are-fixnums-in-emacs-only-29-b

This is why, by default on 32-bit architectures, fixnums in GNU Emacs are 30 bits: http://stackoverflow.com/questions/106597/why-are-fixnums-in-emacs-only-29-bits http://stackoverflow.com/questions/106597/why-are-fixnums-in... http://www.gnu.org/software/emacs/manual/html_node/elisp/Integer-Basics.html http://www.gnu.org/software/emacs/manual/html_node/elisp/Int... SBCL has a more elaborate tag bit system: http://sbcl-internals.cliki.net/tag%20bit http://sbcl-internals.cliki.net/tag%20bit