A=B

 【人は見かけによらぬもの】 らしい....
       Things are seldom what they seem.
       Appearances are deceptive.
       
        ↓の如く 0<a,0<b について A,B を定める;        
A=2 (a + b + Sqrt[2] Sqrt[a b]),

B= 1/2 (a - a^2/(a - 2 b) + 2 b + 3 Sqrt[2] Sqrt[a b] + (Sqrt[2] a Sqrt[a b])/(a - 2 b)
    - (4 a^2)/(-2 a + b) + (2 Sqrt[2] a Sqrt[a b])/(-2 a + b)
    +  2 Sqrt[2]Sqrt[(a^3 - 2 a^2 b + a b (b - 2 Sqrt[2] Sqrt[a b])
    +  2 b^2 (b + Sqrt[2] Sqrt[a b]))^2/((a - 2 b)^2 (2 a^2
    +  2 b (b + Sqrt[2] Sqrt[a b]) - a (3 b + 2 Sqrt[2] Sqrt[a b])))])
        
 A=B を 多様な発想で証明願います;
 ================================== 
 
 https://www.math.upenn.edu/~wilf/AeqB.html 
 https://www.math.upenn.edu/~wilf/AeqB.pdf 
        
  http://web.ydu.edu.tw/~uchiyama/conv/nante.html