incumbent. adj. 1. (often: postpositive and foll by on or upon and an infinitive) morally binding or necessary; obligatory: it is incumbent on me to attend.
Morphea, also known as localized scleroderma, is a condition which causes hardening and discoloration of the skin. It is thought to be isolated to the skin without internal organ involvement as seen in systemic sclerosis (commonly known as scleroderma).
Linear span. In linear algebra, the linear span (also called the linear hull or just span) of a set of vectors in a vector space is the intersection of all subspaces containing that set. The linear span of a set of vectors is therefore a vector space. Spans can be generalized to matroids and modules.