Strange CORRESPONDS TO glyph

From: Markus Kuhn (
Date: Mon Sep 07 1998 - 10:49:25 EDT


I find the glyph used for U+2258 CORRESPONDS TO in ISO/IEC 10646-1 (and
I assume also Unicode) rather strange. It looks like an EQUALS SIGN with
an INVERTED BREVE above. However, the only "corresponds to" sign that I
have seen widely used in the mathematics literature looks roughly like
an EQUALS SIGN with a wide CIRCUMFLEX ACCENT above it.

This is not just my personal experience and what I have learned at high
school and university math courses: ISO 31-11, which defines large parts
of the common mathematical notation to be used in international
scientific publications, also shows in item 11-5.4 a "corresponds to"
symbol consisting of an equals sign and a circumflex accent that is as
wide as the equals sign.

Strangely, the U+2259 ESTIMATES glyph in ISO/IEC 10646-1 looks *much*
closer to a real "corresponds to" sign than the glyph given with U+2258.
I am not familiar with any "estimates" symbol, but could it be possible
that the two glyphs for U+2258 and U+2259 have been mixed up
accidentally in the preparation of ISO 10646-1 and Unicode 2.0?


Markus G. Kuhn, Security Group, Computer Lab, Cambridge University, UK
email: mkuhn at,  home page: <>

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