∃!

See also: 티, ∃, Ǝ, ∄, and Appendix:Variations of "e"

Translingual

Symbol

∃!

1. (mathematics) The symbol used in predicate calculus, etc, to represent the unique existential quantifier, meaning "there exists exactly one".

   (∃!x: P(x)) ↔ ∃x:(P(x) ∧ ∀y:(P(y) → (y = x)))

See also

• ∀
• ∃