ref: 7a447151ae273bf08e596f57b7b9aaa1de11da33 dir: /sys/src/cmd/diff/test/merge-t4.expected/
1 2 3 <<<<<<<<<< merge-t4.l 4 x 6 7 ========== original 4 5 6 7 ========== merge-t4.r w x y z >>>>>>>>>> 8 9 10