TITLE: Symbol denoting "for at least one"
QUESTION [7 upvotes]: As a lazy mathematician, I'm tired of having to write "for at least one". Similar to the $\forall$ (for all) symbol, does a symbol exist to denote "for at least one"? I've been abbreviating to f.a.l.o., but I was hoping for some more elegant notation.

REPLY [2 votes]: Based on what I've read, it sounds like there is no standard abbreviation of "for at least one" or "for some", but what I typically use to denote "for some" in my own personal notes is the inverted F: $\Finv$ (LaTeX \Finv)
It felt like a natural fit since it resembles the existential symbol $\exists$ (whose meaning it shares) just with the top line removed, and "F" is the first sound in the phrase "for some". I commonly use it when I wish to put an existential quantifier after what it quantifies over (improper as it may be), e.g.
$$ x+1 = 2 \quad \Finv\ x $$
I considered using $\exists$ for this purpose, but that felt awkward since "for some" has no initial "E" sound, and it would be confusing to have to remember to read $\exists$ as "for some" only when it is placed after a formula.