complex; nowait;
border(1,0,1,10) begin x:=t; y:=0; end;
border(1,0,1,10) begin x:=1; y:=t; end;
border(2,0,1,10) begin x:=1-t; y:=1; end;
border(1,0,1,10) begin x:=0; y:=1-t; end;
buildmesh(200);
solve(u) /* observe than Re(u) = Im(u) */
begin
onbdy(1,2) u=0;
pde(u) id(u)-laplace(u)=1+I ;
end;
v=Im(u);
plot(u);plot(v);plot(u-v);