First we use a logical style, and then we modify it with a physical style
Logical style should override the current physical style but not all browser complies - it makes the results unpredictable.
Even if results are correct in your Web browser you have no guarantee that they are correct in another browser or even if the page will still look the same ion a new version of your favorite browser. Just do not do it.
This is a regular text. This is bold. This is still bold This is a regular text once again.
This text has a missing closing bold tag.
This is a regular text.