<Phantom_Hoover> learn composition is where you take morphisms such as Phantom and Hoover from the Pha category and combine them together: Hoover \xe2\x88\x98 Phantom.

#!/bin/sh
topic=$(echo "$1" | tr A-Z a-z)
[ -e "wisdom/$topic" ] || { echo "$1? ¯\(°_o)/¯"; exit 1; }
cat "wisdom/$topic"