Turned A
Turned A is a symbol based upon the letter A.
Lowercase ɐ is used in the International Phonetic Alphabet to identify the near-open central vowel. This is not to be confused with the turned alpha or turned script a, ɒ, which is used in the IPA for the open back rounded vowel.
It was used in the 18th century by Edward Lhuyd and William Pryce as a phonetic character for the Cornish language. In their books, both Ɐ and ɐ have been used. It was used in the 19th century by Charles Sanders Peirce as a logical symbol for 'un-American'.
The symbol ∀ has the same shape as a capital turned A, sans-serif. It is used to represent universal quantification in predicate logic. It was first used in this way by Gerhard Gentzen in 1935, by analogy with Giuseppe Peano's turned E notation for existential quantification and the later use of Peano's notation by Bertrand Russell. In traffic engineering it is used to represent flow, the number of units passing a point in a unit of time.
is used in the Uralic Phonetic Alphabet.Encodings
