Expression 3: "A" left parenthesis, "L" , right parenthesis equals StartRoot, "L" left bracket, 1 , right bracket squared plus "L" left bracket, 2 , right bracket squared , EndRootAL=L12+L22
3
Expression 4: "P" left parenthesis, "x" , "y" , right parenthesis equals "M" left parenthesis, "M" left parenthesis, "M" left parenthesis, "M" left parenthesis, "M" left parenthesis, "M" left parenthesis, "M" left parenthesis, "M" left parenthesis, "M" left parenthesis, "M" left parenthesis, "M" left parenthesis, "M" left parenthesis, "M" left parenthesis, "M" left parenthesis, "M" left parenthesis, "M" left parenthesis, "M" left parenthesis, "M" left parenthesis, left bracket, "x" , "y" , "x" , "y" , right bracket , right parenthesis , right parenthesis , right parenthesis , right parenthesis , right parenthesis , right parenthesis , right parenthesis , right parenthesis , right parenthesis , right parenthesis , right parenthesis , right parenthesis , right parenthesis , right parenthesis , right parenthesis , right parenthesis , right parenthesis , right parenthesisPx,y=MMMMMMMMMMMMMMMMMMx,y,x,y