“…Using Maple to verify the correctness of(20) as follows: >evalf(Doubleint(exp(-5*x1-4*x2)*(cosh(7*x1+4*x2))^(2/ 3),x1=-4..-2,x2=-2..3),22); >evalf(1/2^(2/3)*sum(product(2/3-j,j=0..(m-1))/m! *(exp(58 /3-28*m)-exp(116/3-56*m))*(exp(-20+24*m)-exp(40/3-16 *m))/((-29/3+14*m)*(-20/3+8*m)),m=0..infinity),22); On the other hand, by Case (A) of Corollary 1, we obtain of (21) as follows: >evalf(Doubleint(exp(-5*x1-4*x2)*(cosh(7*x1+4*x2))^(2/ 3),x1=0..infinity,x2=0..infinity)); 1.420430140 >evalf(1/2^(2/3)*sum(product(2/3-j,j=0..(m-1))/(m!…”