diff demo

bash-4.2$ diff <(seq 10) <(seq 3;seq 8 10)
4,7d3
< 4
< 5
< 6
< 7

bash-4.2$ diff -y <(seq 10) <(seq 3;seq 8 10)
1                                                               1
2                                                               2
3                                                               3
4                                                             <
5                                                             <
6                                                             <
7                                                             <
8                                                               8
9                                                               9
10                                                              10

bash-4.2$ diff -y --suppress-common-lines <(seq 10) <(seq 3;seq 8 10)
4                                                             <
5                                                             <
6                                                             <
7                                                             <