The problem is simple but maybe there is solution. I have large file in $Mathematica$ but some calculation I should continue in Maple and I have problem with opening .nb file in Maple. Derivatives don't work and lot of mistakes in recognizing. This is one simple example
Plus[Times[-1,A1,Derivative[0,1,1][P][x,y,z]],Times[A3,Derivative[0,0,1][P][x,y,z][x,y,z]],Times[-1,A2,Derivative[0,1,0][Q][x,y,z][x,y,z]]]