1. Apparatus for obtaining a digital value of a function expressed by: EQU w = .SIGMA. a.sub.i.sbsb.1i.sbsb.2. .. i.sub..sbsb.j.. . i.sbsb.nx.sub.1.sup.i.sbsp.1 x.sub.2 .sup.i.sbsp.2. .. x.sub.j.sup.i.sbsp.j. .. x.sub.n.sup.i.sbsp.n where w is the function the value of which is to be obtained, a.sub.i.sbsb.1i .sbsb.2i.sbsb.j.. . i.sbsb.nn 's are constants, x.sub.1, x.sub.2,. .. , x.sub.j,. .. , x.sub.n are the independent variables, i.sub.j = 0, 1, 2,. .. , m.sub.j, and at least one of m.sub.j 's .gtoreq. 2, where j = 1, 2,. .. , n and represents the dimension of a multidimensional function, wherein n .gtoreq. 2.sup., comprising: a. memories designated by multi-dimensional addresses (i.sub.1, i.sub.2,. .. , i.sub.j,. .. , i.sub.n) where i.sub.j = 0, 1, 2,. .. , m.sub.j and at least one m.sub.j .gtoreq. 2, each memory having a word length and means for loading said memories with respective, specific, initial numerical values determined by the constants a.sub.i .sbsb.1i.sbsb.2.. . i.sbsb.j. .. i.sbsb.n 's, b. means for performing algebraic additions of the contents of the memories designated by the addresses (i.sub.1, i.sub.2,. .. , i.sub.j.sub.-1, i.sub.j + 1, i.sub.j.sub.+1,. .. , i.sub.n) to the contents of the memories designated by the addresses (i.sub.1, i.sub.2,. .. , i.sub.j.sub.-1, i.sub. j, i.sub.j.sub.+1,. .. , i.sub.n) for i.sub.j = 0, 1, 2,. .. , m.sub.j -1 in a predetermined sequence, said algebraic additions being performed with respect to every combination of i.sub.1, i.sub.2,. .. , i.sub.j.sub.-1 and at least i.sub.j.sub.+1 = 0, i.sub.j.sub.+2 = 0,. .. , i.sub.n = 0 in corresponding cycles, said means for performing algebraic additions including: b-1. adder means, b-2. means for selectively interconnecting the outputs and inputs of said memories and said adder means for each said cycle of algebraic additions and for maintaining said interconnections during each said cycle, and b-3. means to control said interconnecting means and said adder means to perform a number of said cycles of algebraic additions in total corresponding to the value of each variable x.sub.j for all of the variables x.sub.j, where j = 1, 2,. .. , n whereby the value of the function w is obtained in the memory of address (0,0,0,. .. , 0).