null set
Mathematical zero membership
A null set is a set containing no elements—the empty set.
In mathematics, it's denoted by ∅ or empty braces .
The concept is fundamental to set theory: every set contains the null set as a subset.
The set of married bachelors is a null set.
Absence of substance
- nothingnessComplete absence of existence
- voidWithout legal effect
- absenceState of not being
- nonexistenceAbsence of being
negation · zero · vacuity · nihilism · blankness · placeholder · starting point · baseline
Collection within collection
- cardinalitySize of a set
- elementBasic substance or factor
- membershipState of belonging
- complementWhat makes complete
intersection · union · disjoint · Venn diagram · finite · infinite · partition · equivalence
emptiness
Absence of substance
- nothingnessComplete absence of existence
- voidWithout legal effect
- absenceState of not being
nonexistence · negation · zero · vacuity · nihilism · blankness · placeholder · starting point · baseline · foundation
subset
Collection within collection
- cardinalitySize of a set
- elementBasic substance or factor
- membershipState of belonging
complement · intersection · union · disjoint · Venn diagram · finite · infinite · partition · equivalence · injection