<oerjan> learn `edit <file> gives you a url, then in your browser: (1) Press Fetch (2) Make your changes (3) Press edit (4) Paste the command line at the top into the channel.

|a+b@| = { √(a²-b²) if a²-b² ≥ 0 ; i√(a²-b²) if a²-b² < 0 }