[Solved] Modern Algebra Symbols

[Hagar Delest]

I have noticed that there are some symbols that are used in Modern (abstract) Algebra, that aren't necessarily listed in the math reference. "oplus", indicating a direct product between 2 groups, is one such example. I would like to track down a few others.

My most pressing need, is the sign for "is isomorphic to". (a tilde above an equal sign) How do I make this?

[UnklDonald418]

Insert %Ux2245 into the appropriate place in your formula to display the character I believe you are needing.
To find other symbols, in the Math module select Tools>Symbols to open the Symbols dialog.
Select Special for Symbol Set and the click on Edit to open the Edit Symbols dialog.

[MH7]

OK, that's really clunky, but it works. The only question is, how do I put a slash through it, to indicate "is not isomorphic to"?

Thank you.

[UnklDonald418]

that's really clunky, but it works.

If you use the Edit Symbols dialog I mentioned, you can add the symbol to the list of Special symbols. Once on the list you can select it in the Symbols dialog and Insert it into your formula.

how do I put a slash through it, to indicate "is not isomorphic to"?

The Unicode value should be %Ux2247 but it doesn't seem to work so it may not be available in the Math module.

[Zizi64]

My most pressing need, is the sign for "is isomorphic to". (a tilde above an equal sign) How do I make this?

I just tried it in my LibreOffice 5.4.7:

for the ≅ sign like character (it will be a composed character but not one standalone Unicode character):

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tilde "=" 

For the "approximately equals" sign:

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simeq

And I can write Oplus characters in my LO. Maybe the working of this feature is depends on the installed Symbols character set. There are obsolete Symbols set in some version of the operating systems.

[keme]

The congruence/isomorphism symbol is hex unicode 2245.

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A boper %Ux2245 B

"Boper" is perhaps not strictly necessary. It makes the symbol behave like a binary operator, which improves layout in some situations (and may also aid in discovering structural inconsistencies in your formula).

[MH7]

Thank you everyone for the suggestions. Regarding the "clunky" use of the special characters, I say that it was clunky, because in the formula editor, it would not allow me to directly insert using the Unicode. I did, indeed, have to add it to the special characters menu, under "edit". And it seems that is a limited palette.

Now, the pressing issue, is the question that was missed in here... Where is the "not isomorphic to" symbol? How can I put a slash through what we've just discovered, to negate its value?

[MrProgrammer]

Where is the "not isomorphic to" symbol?

Perhaps you can use:

tilde "≠"

If this solved your problem please go to your first post use the Edit button and add [Solved] to the start of the title. You can select the green checkmark icon at the same time.

[MH7]

It works OK (doesn't quite look right) in the document, but not in the math editor.

[UnklDonald418]

how do I put a slash through it, to indicate "is not isomorphic to"?

I found it in the Arial Unicode MS font. Set the Edit Symbol dialog like this

Select the symbol and push the Add button. Then it should appear in the Symbols dialog Special list.

[MH7]

THank you, that will do it.