I don't understand this

[Daniel]

On 2023-06-10 21:49, Richard Kimberly Heck wrote:
> On 6/10/23 02:17, Daniel wrote:
>> On 2023-06-10 05:54, Tom Goldring wrote:
>>> If I put in the [\mathbb] "R" followed by _\aleph_0, the R and the 
>>> aleph show up correctly, but the zero (the subscript of the aleph) 
>>> shows up as a different character (I think it's the character that's 
>>> used in formal logic to mean something like "is not a proof of").
>>
>> I do not know why it is showing different symbols. 
> 
> It's because the 'blackboard' font is quite limited (to ASCII caps, I 
> think). If you type characters not present in that font, you get weird 
> results.
> 
> Riki

I see. Would be better to get an undefined symbol, e.g. questions marks, 
rather than weird symbols. But I guess there is some technical reason 
for this.

Daniel