podzbiorem
Podzbiorem is the instrumental form of the Polish term podzbiór, used in mathematics to refer to the concept of a subset. In set theory, a set A is a subset of a set B if every element of A is also an element of B. Notation: A ⊆ B denotes a (not necessarily proper) subset, while A ⊂ B is commonly used to indicate a proper subset, where A ≠ B. The empty set ∅ is a subset of every set, and every set is a subset of itself (reflexivity).
Examples help illustrate the idea. Let A = {1, 3, 5} and B = {1, 2, 3, 4, 5}.
Subsets support basic operations. If A and B are subsets of a universal set U, then A
In Polish mathematical usage, podzbiór (and its instrumental form podzbiorem) is used similarly to denote a