regex101: DSL tags missing closing pair tags

\[the literal [ (91₁₀ / 133₈ / 5B₁₆)

bthe literal b (98₁₀ / 142₈ / 62₁₆) (case sensitive)

\]the literal ] (93₁₀ / 135₈ / 5D₁₆)

Negative Lookahead(?!\w*.\[\/b\])

\w*any word character, repeated any number of times

.any character (except for line terminators)

\[the literal [ (91₁₀ / 133₈ / 5B₁₆)

\/the literal / (47₁₀ / 57₈ / 2F₁₆)

bthe literal b (98₁₀ / 142₈ / 62₁₆) (case sensitive)

\]the literal ] (93₁₀ / 135₈ / 5D₁₆)

Global pattern flags

g modifier: global. Finds all matches instead of stopping after the first

m modifier: multiline. Causes ^ and $ to match the start and end of each line, not only the start and end of the string

Search reference

Regular Expression

\[b\](?!\w*.\[\/b\])

New

By purely mathematical reasoning it is possible [b]to demonstrate ([i]or[/i] [b]prove) a theorem which...
[b]There is little point ([i]or[/i] [b]sense) in listing all of the known amino acids.
Much of the gravel is used [b]"as is" ([i]соl.[/i]) for building roads.
Tuberculin test [b]is of doubtful value in the elderly since its interpretation is very difficult.
[b](As) viewed from the top ([i]or[/i] [b]from above) the insect's abdomen swings to the top as if it were a rudder.