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4. Formal Logic / C. Predicate Calculus PC / 2. Tools of Predicate Calculus / e. Existential quantifier ∃

[symbol showing a variable refers to 'at least one' object]

4 ideas
There are four experiences that lead us to talk of 'some' things [Russell]
'Some Frenchmen are generous' is rendered by (∃x)(Fx→Gx), and not with the conditional → [Lemmon]
∃y... is read as 'There exists an individual, call it y, such that...', and not 'There exists a y such that...' [Hart,WD]
Existential Generalization (or 'proof by example'): if we can say P(t), then we can say something is P [Wolf,RS]