Co-articulated consonant consonant such as is doubly or secondarily articulated. In some English dialects, for example, is a labialized velar that could be transcribed as , but the Japanese is closer to a true labial-velar, . It is common usage to restrict the letter to the former. The glottis controls phonation, and works simultaneously with many consonants. It is not normally considered an articulator, and an ejective such as , with simultaneous closure of the velum and glottis, is not normally considered to be a co-articulated consonant. Co-articulated consonant Co-articulated consonants or complex consonants are consonants produced with two simultaneous places of
Closure with a twist Closure with a twist Closure with a twist is a property of subsets of an algebraic structure. A subset formula_1 of an algebraic structure formula_2 is said to exhibit closure with a twist if for every two elements there exists an automorphism formula_4 of formula_2 and an element formula_6 such that where "formula_8" is notation for an operation on formula_2 preserved by formula_4. Two examples of algebraic structures which exhibit closure with a twist are the cwatset and the generalized cwatset, or GC-set. In mathematics, a cwatset is a set of bitstrings, all of the same length, which is closed