Обозначение для { f(x) | x ∈ A }

[3D Homer]

В книге F.R. Drake, D.Singh. Intermediate Set Theory. Wiley, 1996. P. 216 написано:

[We write] $f''z$ for the image of $z$ under $f$ , i.e. $\{f(x)\mid x\in z\}$, the set of values of $f$ for arguments in $z$. Note that $f'' z = \mathrm{ran}f\upharpoonright z$. Alternatives: there are many, e.g. $f * z$, $f[\![z]\!]$, and even $f(Z)$, in cases where it is clear that $Z$ could not be an argument for $f$ but must be treated as a set of arguments (in which case the arguments for $f$ would be denoted by lower­case letters). We must treat this usage with care within set theory, where every object is a set; but it is very common, and sometimes natural.

Мне кажется, я тоже видел $f[Z]$ где-то еще.