Close-mid central unrounded vowel Close-mid central unrounded vowel The close-mid central unrounded vowel, or high-mid central unrounded vowel, is a type of vowel sound, used in some spoken languages. The symbol in the International Phonetic Alphabet that represents this sound is . This is a mirrored letter e, and should not be confused with the schwa , which is a turned e. It was added to the IPA in 1993; before that, this vowel was transcribed (Latin small letter e with umlaut, not Cyrillic small letter yo). Certain older sources transcribe this vowel . The letter may be used with a lowering diacritic ,
Power residue symbol Hilbert symbol formula_24 for the prime formula_4 by in the case formula_4 coprime to "n", where formula_28 is any uniformising element for the local field formula_29. The formula_14-th power symbol may be extended to take non-prime ideals or non-zero elements as its "denominator", in the same way that the Jacobi symbol extends the Legendre symbol. Any ideal formula_31 is the product of prime ideals, and in one way only: The formula_14-th power symbol is extended multiplicatively: For formula_35 then we define where formula_37 is the principal ideal generated by formula_38 Analogous to the quadratic Jacobi symbol, this symbol is multiplicative