4 ms·

Blackboard Bold

• LanternLight83 3y ago
  > When Knuth's 1984 The TeXbook needed an example of blackboard bold for the index, he produced ℝ using the letters I and R with a negative space between; in 1988 Robert Messer extended this to a full set of "poor person's blackboard bold" macros, overtyping each capital letter with carefully placed I characters or vertical lines. > Not all mathematical authors were satisfied with such workarounds.
• jjgreen 3y ago
  Don't mention blackboard bold in typeset material around mathematicians, it always ends in a fight.