Glottalization only affects open syllables and syllables ending in a continuant or a vowel. The categories and roughly correspond to the modern terms "continuant" and "stop". A voiced velar continuant occurred distinctively in older Standard Danish. The determinant of a tridiagonal matrix is given by the continuant of its elements. Navajo also does not have consistent phonetic voicing in the "voiced" continuant members. In Muir's book the generalized continuant is simply called continuant. By implication, the class is also described as "not" having the features [+continuant] or [+voice]. In phonology, continuant as a distinctive feature also includes trills. Whether lateral fricatives and approximants and taps/flaps are continuant is not conclusive. However, in some noun stems, the stem-initial continuant does not voice when intervocalic&colon; ('salt').