- In predicate logic, an existential quantification is a type of quantifier, a logical constant which is interpreted as “there exists”, “there is at least one”, or “for some”. It is usually denoted by the logical operator symbol ∃, which, when used together with a predicate variable, is called an existential quantifier ("∃x" or “∃(x)” or “(∃x)”). Existential quantification is distinct from universal quantification (“for all”), which asserts that the property or relation holds for all members of the domain. Some sources use the term existentialization to refer to existential quantification.
- Lake Shannon (Wikipedia)
Lake Shannon is a long, narrow reservoir on the Baker River in Skagit County, Washington in the United States. Formed in the 1920s by the construction of an arch dam just above the town of Concrete, the lake is approximately 7.5 miles (12 km) long and averages 0.6 miles (1 km) wide when full. Located just outside the western boundary of North Cascades National Park, Lake Shannon serves as the lower reservoir for Puget Sound Energy’s Baker River Hydroelectric Project.
