back to root folder using double dot only - should go to /index.html

back to root folder using double dot and file name - should go to /index.html

back to root folder using dot slash double dot and file name - should go to /index.html

sibling no dot - should go to /sub/index3.html

sibling with dot - should go to /sub/index3.html

sibling with parent and then sub - should go to /sub/index3.html