s/^\(.*\) \1/\1 = \1/ te h s/..\(.*\)../\1/ :a /^ $/bs /^ /bl / $/bg s/.\(.* \)./\1/ ba :s x h :q s/^\(.\)\(.* \)\1/\2/ tq s/$/@9876543210/ /^\(.\).* \(.\).*@.*\1.*\2/bg :l x s/ / < / be :g x s/ / > / :e
Note that non-ascii characters in the above source code will be escaped (such as \x9f).