Existential quantifier

Existential quantifier is a logical operator of predicate logic, written ThereIs, which makes it possible to express that at least one entity in the universe of discourse has a particular property.

Example
in (i), ThereIs is used to express that there is at least one entity x which has property P:

(i) ThereIs(x) [ P(x) ]

The existential quantifier can be used to represent the meaning of indefinite noun phrases:

(ii) John ate a donut ThereIs(x) [ donut(x) &amp; ate(john,x) ]

Link
Utrecht Lexicon of Linguistics