GNU/Linux Desktop Survival Guide by Graham Williams
Desktop Survival Project Home Preface Advocacy History Distributions Installation Basic Survival Wajig Audio AbiWord APM Backup Bash Booting Cameras CD Chinese ChRoot Clock Commercial Conference Management Configuration CRON CVS Databases DIA Directories Disks Documentation DVD Email Eye of Gnome Evolution File Systems Firewalls Floppy Disks Fonts Ghemical GIMP Glade Gnome GnuCash Gnumeric GQView Graphics Groups HTML Editors ImageMagick Initialisations on Booting Java KDE Kernels Keyboard Konqueror KVM Switch LaTeX Log System Login Magellan Mathematics Memory Modems Mounting Devices MS/Windows Music MySQL Nautilus Networks NFS NT File System OpenOffice.org Oracle Packages Partitions Passwords PDF Photos PPP Presentations Printing Python R Remote Desktops Rsync Samba Scanning Science Security SH File System Sketch Spell SPlus Spruce SSH SUDO Subversion Swap Themes USB Video Virtualization Web Word X XML Sample Installations Troubleshooting Index

Ladder

Ladders are used as a pseudo-electric representation of boolean expressions. They are used by some vendors of industrial automats (including Schneider/Télémécanique and Siemens).