ref: 7b3bb0ea7536e695061d68d5d0710a6f0e7aa3bc dir: /sys/src/cmd/diff/test/merge-t3.expected/
1 2 3 4 <<<<<<<<<< merge-t3.l y ========== original 5 ========== merge-t3.r x >>>>>>>>>> 6 7 8 9 10