Chronozone

A chronozone or chron is a slice of time that begins at a given identifiable event and ends at another. Such tracer events are usually keyed to the disappearance (extinction) of fossils of a widely distributed and rapidly changing species or the appearance of such a species in the geological record. Researchers use chronozones or chrons especially frequently in the various disciplines related to geology, notably in stratigraphy where they contribute to relative dating.

Events susceptible to identification and analysis by the physical sciences (such as Earth's magnetic-field reversals or the location of a combination of chemical evidence in a layer corresponding to the meteor strike believed to have caused the extinction of the dinosaurs) can also help define chronozones. Hence chronozones, and the international identification and acceptance of widespread chronozones as official useful markers or benchmarks of time in the rock record, are non-hierarchical in that chronozones do not need to correspond across geographic or geologic boundaries, nor be equal in length (despite an early constraint that one be defined as smaller than a geological stage). A chronozone is usually defined in geologic terms for a geographical area by fossil names (biozone or biochronozone) or in worldwide terms by geomagnetic-reversal identifiers (polarity chronozone).

WGIB

WGIB (91.9 FM) is a non-profit radio station that originates programming from Birmingham, Alabama, USA. The station is currently owned by Glen Iris Baptist School, and is licensed to serve Birmingham, Alabama, USA. The station was assigned the WGIB call letters by the Federal Communications Commission on September 20, 1982.

WGIB carries Christian preaching and gospel music 24 hours a day, much of which originates from the church's studios. WGIB is also relayed on a series of low-powered FM translators and full-powered WQEM at 101.5 MHz in Columbiana, Alabama. The station's audio is also streamed on the internet.

Simulcast

WQEM (101.5 FM) is a radio station broadcasting a Religious radio format as a simulcast of WGIB. WQEM is licensed to serve Columbiana, Alabama, USA. The station is currently owned by Glen Iris Baptist School.

WQEM was purchased from Clear Channel Communications in 2002. Glen Iris kept the WQEM call sign for the station after its purchase. The station was assigned the WQEM call letters by the Federal Communications Commission on August 3, 1998. Before its purchase by Glen Iris Baptist School, WQEM served as a repeater of Top 40 station WQEN, whose signal at the time did not adequately cover the southern suburbs of Birmingham.

Universal quantification

In predicate logic, a universal quantification is a type of quantifier, a logical constant which is interpreted as "given any" or "for all". It expresses that a propositional function can be satisfied by every member of a domain of discourse. In other words, it is the predication of a property or relation to every member of the domain. It asserts that a predicate within the scope of a universal quantifier is true of every value of a predicate variable.

It is usually denoted by the turned A (∀) logical operator symbol, which, when used together with a predicate variable, is called a universal quantifier ("∀x", "∀(x)", or sometimes by "(x)" alone). Universal quantification is distinct from existential quantification ("there exists"), which asserts that the property or relation holds only for at least one member of the domain.

Quantification in general is covered in the article on quantification (logic). Symbols are encoded U+2200 ∀ FOR ALL (HTML ∀ · ∀ · as a mathematical symbol).