As far as I know, I was the first person who brought up the idea of using some new Hebrew letters as mathematical symbols beside , . It grew out of a discussion with a Jewish friend on one of his blog posts. Let me add some points before voting about usefulness of this approach.
There could be some difficulties in using Hebrew letters as mathematical notations:
- A possible problem is that many Hebrew letters are so similar to each other that makes it hard for non-native or non-expert people to distinguish between them particularly when we are writing them by hand, say on a blackboard. For example there could be confusions between Bet (ב), Kaf (כ) and Nun (נ) or between Dalet (ד) and Resh (ר).
- Also due to the similarity between many Latin and Greek letters on one hand and Hebrew characters on the other hand, some confusions could arise if we add some particular Hebrew letters to our current mathematical symbols. For example and final Tsadi (ץ) or and final Mim (ם) are similar.
- There is a difference between “hand-written” and “typed” forms of Hebrew letters. It could make some confusion for people even for native Hebrew speakers (see Cursive Hebrew).
- It is not clear whether the majority of mathematical community who are not native Hebrew speakers are comfortable with using these new symbols or not.
There are also some advantages in using new Hebrew letters. For example:
- In many cases in mathematics we use different forms of a single Latin letter, say , , , , , , and . These are different forms of “M” which are almost indistinguishable in writing by hand on a paper or chalkboard. In such cases it needs some extra effort to make the difference clear for the audience. Maybe using some equivalent Hebrew letters could help in this direction for example the Hebrew equivalent of “M” is Mim (מ) and the Hebrew equivalent of “Q” is Qof (ק).
- The new Hebrew letters could represent new mathematical notions particularly those which are of a set theoretic origin. This approach is compatible with the way that the founders of set theory introduced and to mathematics as the symbols of essentially new notions, namely infinite cardinals.
- Almost all of the Latin and Greek letters are present in our current mathematical notations but from Hebrew language just and are used frequently (if you are interested in using new Hebrew letters in some of your papers, see my question on TeX.SE to learn how to type the corresponding LaTeX codes). This is a kind of irregularity. In this direction it seems appropriate to add as much as possible symbols of a certain script to our notation toolbox when a few letters of that particular script are already in use in some disciplines of mathematics.
- Mathematics is a universal language of all humans around the world. Many mathematicians of various cultures contributed to it through history. Making this international language more multicultural in its appearance (as well as its content which is already multicultural) through adding new notations of different backgrounds looks like an appropriate idea compatible with promotion of the international idea of cultural tolerance and mutual understanding between people of different cultural backgrounds.
As the conclusion let me add that I think many Hebrew letters like ל , מ, ש, צ , ע are easy to write and suitable for daily mathematical use at least in set theory, however I have no idea about the general opinion of majority of mathematicians towards this topic or similar approach about the interesting symbols of other languages. The following poll is intended to reveal the public opinion on this, thus please cast your vote and let us know about your reasons in comments. Thanks in advance!