"The symmetry is a smooth (differentiable to all orders) invertible transformation
mapping solutions of the ODE to solutions of the ^ODE^. Invertible means the Jacobian is nonzero:
x'x y'y - x'y y'x != 0"
10-15% of first year salary sounds like a laughably high commission. Surely it can't cost >$5K to find a good coder... Frankly, I don't see why it should cost more than 1K, tops, to find an excellent, excellent coder...