Notation for non-empty subset
71725
$\mathcal N (A):=\mathcal P(A)\setminus\{\varnothing\}$ notation
120610
Find a subset of $S = \{(1, 0, i), (i, 2, -3), (2-i, 1+i, i)\}$ that forms a basis for $\textsf V = \operatorname{span}(S)$
127100
Countable or uncountable set 8 signs
123498
Is "empty set" an element of a set?
134177
Using setminus notation with set elements
45485
Dimension of a subset
110485
Nested sequence of non-empty compact subsets - intersection differs from empty set
95373
Additive set function on a semiring of sets
38685
Notation for discrete intervals
118145
Mathematical symbol for disjoint set union
120235
Clarification of the notation $f: \mathbb{R} \setminus\{3\} \to\mathbb{R}\setminus\{2\}$
19260
What does the notation $q^k || n$ mean?
110669
Linear span of the empty set
108516
"Not empty" set in one word?
130418
Is ${\{\emptyset,\{\emptyset\},\{\{\emptyset\}\},\{\{\{\emptyset\}\}\},...\}} $ a set?
30660
Empty set does not belong to empty set
28523
When would the intersection of the empty set mean anything?