# How to pronounce $\mathcal{E}$?

How to say $\mathcal{E}$ when we are speaking about mathematics? Can I call it "curly E"?

And also how to pronounce $\mathcal{A}$ and $\mathcal{B}$ and $\mathcal{P}$ and so on?

• Why should anyone bother answering if you're planning to delete their answer? Jan 21 '18 at 3:29
• > I may delete it once I get the answer.
– user223391
Jan 21 '18 at 3:37
• This is something you can google for Jan 21 '18 at 3:45
• I cannot type strange letters on google Jan 21 '18 at 3:48
• For future reference, you cannot delete a question once someone has spent time and energy answering it. Jan 21 '18 at 4:24

It depends on your audience and the context. In physics, $\mathcal E$ usually denotes emf, so you would say that. In set theory, $\mathcal P$ usually denotes a power set, so you would say that. Otherwise, just do your best to describe it in a manner that your audience would understand. “Curly” or “calligraphic” works fine in my opinion.

Side note: You actually can type $\mathcal E$ into Google if you use the Unicode character ℰ (U+2130).

A useful resource for "speaking" mathematics is The Handbook for Spoken Mathematics by Lawrence A. Chang. This book suggests that we should use a description of the font or script, plus the name of the letter (see pages 3–5). Hence $$\mathcal{E}$$ might be read as "calligraphic capital $$E$$". In most contexts, this would likely be overkill and require too much talking—I gather that much of the intent of the Handbook is to give a guide for instructors of blind students. Hence an abbreviated "calligraphic E" might also be appropriate, as we can rely on students to read / copy what is on the board in most circumstances.

Other thoughts (including those above):

• Follow the handbook: "calligraphic capital [letter]" or "calligraphic [letter]".
• Describe the letter more loosely: "script [letter]", "curly [letter]", or "cursive [letter]".
• Use TeX: "mathcal [letter]" or "cal [letter]".[1]
• Don't Sweat It: "[letter]".[2]
• Name the Symbol from Context: as suggested in this answer, the symbols may have specific meaning in a given context. For example, $$\mathcal{H}$$ is "the Hilbert space H", and the symbols $$\mathcal{X}$$ and $$\mathcal{Y}$$ are "the Banach spaces $$X$$ and $$Y$$".

[1] This is what I find myself doing most often. The symbol $$\mathscr{H}$$ is "math script H", while $$\mathfrak A$$ is "mathfrak A". This sometimes causes me problems in classrooms where I am dealing with students who don't know TeX, but has never been an issue when talking with my peers.

[2] This option will often be the most appropriate. For example, the space of distributions $$\mathcal{E}'$$ is just "E prime". There may be potential for ambiguity, but in many, many contexts, it just won't be a problem. I mean, do we often make a big deal about an element $$x$$ in a space $$X$$? Sometimes we carefully speak the letters out loud, but I find myself saying "Let eks be an element of eks..." more often than I care to admit.