.ll 25 .pl 20 .nf file1 and file2 #1 [[ file1 only ]] . .mc | file2 only file2 only .mc file1 and file2 #2 .mc + file2 only .mc file1 and file2 #3 [[ file1 only file1 only ]] . .mc * .mc file1 and file2 #4 file1 and file2 #5