Complex sentence: John W. Herivel (born 1918 or 1919) was a British codebreaker at Bletchley Park during World War II, and discoverer of the Herivel tip, also known as Herivelismus.
Split into simpler sentences: John W. Herivel (born 1918/1919) is former World War II codebreaker at Bletchley Park. As a codebreaker, Herivel is remembered as the discoverer of what was quick dubbed the Herivel tip, also known as Herivelismus.