procedure POLIN2(X1A,X2A:array of real;YA:matrx2; M, N:integer;
                                      X1, X2:real;var Y, DY:real);
var
    YNTMP,YMTMP:array[0..20] of real;
    J,K:integer;
begin
    For J:=1 To M do
    begin
        For K:=1 To N do
            YNTMP[K]:=YA[J, K];
        POLINT(X2A,YNTMP, N, X2, YMTMP[J], DY);
    end;
    POLINT(X1A, YMTMP, M, X1, Y, DY);
end;