Description: Define restricted
universal quantification. Special case of Definition
4.15(3) of [TakeutiZaring] p. 22.
Note: This notation is most often used to express that 𝜑 holds for
all elements of a given class 𝐴. For this reading Ⅎ𝑥𝐴 is
required, though, for example, asserted when 𝑥 and 𝐴 are
disjoint.
Should instead 𝐴 depend on 𝑥, you rather focus on
those 𝑥
that happen to be contained in the corresponding 𝐴(𝑥). This
hardly used interpretation could still occur naturally. For some
examples, look at ralndv1 44269 or ralndv2 44270, courtesy of AV.
So be careful to either keep 𝐴 independent of 𝑥, or
adjust your
comments to include such exotic cases. (Contributed by NM,
19-Aug-1993.) |