Added June 2, 2019.
From example 3.5.6, page 214 nonlinear pde’s by Lokenath Debnath, 3rd edition.
Solve for \(u(x,y)\) \begin {align*} u_x-u_y&=1 \end {align*}
with \(u(x,0)=x^2\)
Mathematica ✓
ClearAll["Global`*"]; pde = D[u[x, y], x] - D[u[x, y], y] ==1; ic = u[x,0]==x^2; sol = AbsoluteTiming[TimeConstrained[DSolve[{pde,ic} ,u[x, y], {x, y}], 60*10]];
\[\left \{\left \{u(x,y)\to x^2+2 x y+(y-1) y\right \}\right \}\]
Maple ✓
restart; pde := diff(u(x,y),x)-diff(u(x,y),y)=1; ic := u(x,2)=x^2; cpu_time := timelimit(60*10,CodeTools[Usage](assign('sol',pdsolve([pde,ic],u(x,y))),output='realtime'));
\[u \left ( x,y \right ) = \left ( -2+x+y \right ) ^{2}+2-y\]
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