I would like to produce a variant of letter
a as shown below
The source is Shoenfield's Mathematical Logic book (first occurrence in p18) and it is used to denote structures. It appears (to me) like a large calligraphic variant of lowercase
a. I use
\cal A instead, and I have also looked over some other alternatives (e.g. the
\frac ones) but I would like to use that precise symbol in my notes if possible.
The results from detexify were not really that useful in this case either: