I want to relate the solvability to planar ODEs to weak differential solvabilty of first order PDEs, e.g.
what does solability or special properties of
f:=(P,Q) contunous differential and real-valued
solvabilty of PDEs
with g>0 a.e. in some simple connected domain of the plain
B (at least) weak diffentiable?
Thanks for anz help!