Turned A
Turned A (capital: Ɐ or Ɒ, lowercase: ɐ or ɒ, math symbol ∀) is a symbol based upon the letter A.
Lowercase ɐ (in two story form) is used in the International Phonetic Alphabet to identify the near-open central vowel. A variant, turned alpha, ɒ, is also used in the IPA as the open back rounded vowel.
It was used in the 18th century by Edward Lhuyd and William Pryce as phonetic character for the Cornish language. In their books, both Ɐ and ɐ have been used. [1] It was used in the 19th century by Charles Sanders Peirce as a logical symbol for 'un-American' ("unamerican").[2]
The symbol ∀ has the same shape as a capital turned A, sans serif. It is used to represent universal quantification in predicate logic. When it appears in a formula together with a predicate variable, they are referred to as a universal quantifier. In traffic engineering it is used to represent flow, the number of units (vehicles) passing a point in a unit of time.
Encodings
| Character | Ɐ | ɐ | Ɒ | ɒ | ∀ | |||||
|---|---|---|---|---|---|---|---|---|---|---|
| Unicode name | LATIN CAPITAL LETTER TURNED A | LATIN SMALL LETTER TURNED A | LATIN CAPITAL LETTER TURNED ALPHA | LATIN SMALL LETTER TURNED ALPHA | FOR ALL | |||||
| Encodings | decimal | hex | decimal | hex | decimal | hex | decimal | hex | decimal | hex |
| Unicode | 11375 | U+2C6F | 592 | U+0250 | 11376 | U+2C70 | 594 | U+0252 | 8704 | U+2200 |
| UTF-8 | 226 177 175 | E2 B1 AF | 201 144 | C9 90 | 226 177 176 | E2 B1 B0 | 201 146 | C9 92 | 226 136 128 | E2 88 80 |
| Numeric character reference | Ɐ | Ɐ | ɐ | ɐ | Ɒ | Ɒ | ɒ | ɒ | ∀ | ∀ |
| Named character reference | ∀ | |||||||||
| Symbol font | 34 | 22 | ||||||||
| TeX | \forall | |||||||||
See also
References
- ↑ Michael Everson, Proposal to add Latin letters and a Greek symbol to the UCS, ISO/IEC JTC1/SC2/WG2 N3122 L2/06-266 (2006)
- ↑ Page 320 in Randall Dipert, "Peirce's deductive logic". In Cheryl Misak, ed. The Cambridge Companion to Peirce. 2004