Applied Mathematics and Mechanics (English Edition) ›› 1989, Vol. 10 ›› Issue (2): 183-188.
李秉友
Li Bing-you
摘要: Let X be a convex metric space with the property that every decreasing sequence of nonenply dosed subsets of X with diameters tending to has menemptyintersection. This paper proved that if T is a mapping of a elosed conver nonempty subset K of X into itself satisfying the inequality:
d(Tx,Ty)≤ad(x,t)+b{d(x,Tx)+d(y,Ty)}+c{d(x,Tx)+d(y,Ty)}
for all x,y in K,where 0≤a<1,b≥0,c≥0,a+c≠0 and a+2b+3c≤1, then T has a unique fixed point in K.