چکیده (انگلیسی):

We consider Volterra and Fredholm integral equations for functions with values in L - spaces. This includes corresponding problems for set-valued functions, fuzzy-valued func- tions and many others. We prove theorems of existence and uniqueness of the solution for such equations and suggest some algorithms for finding approximate solutions. We get initial results in the approximation of functions with values in L -spaces by piecewise lin- ear functions and we also get the error estimates of trapezoidal quadrature formulas. We apply these results for analysis of convergence of suggested algorithms.