- Statements with “for all” and “there exist” in them are called quantified statements. “For all”, written with the symbol ∀, is called the Universal Quantifier and and “There Exists” , written with the symbol ∃, is called the Existential Quantifier. A quantifier turns a predicate such as “x is greater than 7” into a statement that can be true for false. For instance, “For all x, x is greater than 7” is false as 2 is not greater than 7, but “There Exists an x such that x is greater than 7” is true as 8 is greater than 7.
- Star Tales - Microscopium (ianridpath.com)
One of the southern constellations representing scientific instruments that were invented in 1751–52 by the French astronomer Nicolas Louis de Lacaille. In this case the instrument concerned is an early form of compound microscope, i.e. one that uses more than one lens.