[Solved] Math formula: not imply, not equivalent ⤃ ⤄

[MilosDj]

Where can I find not equivalent and not imply in math formula editor? I am not able to find it in Relations set.
I tried to fake it with utf8 chars ⤃ ⤄ but it doesnt show at all.
I tried not drarrow, neg drarrow...

[Hagar Delest]

See this tutorial: [TIP] Adding new symbols to Math.
The screenshot to add the symbols (I used the font Symbola on my xubuntu machine):

Please add [Solved] at the beginning of the title in your first post (top of the topic) with the *EDIT button if your issue has been fixed.