Is it possible to simplify this circuit using just parallel and series definitions ?
* A circuit is parallel to another circuit or several circuits if and only if they share common terminals; i.e. if both the branches touch each other's endpoints
* Resistors can be connected in series; that is, the current flows through them one after another
These are the definitions of resistors in series or parallel and according to these definitions none of these are in series or parallel.
This was my attempt at making the circuit a bit easier to simplify but still could not see how any would fit into the definitions.