To (dis)prove termination of C programs, AProVE uses symbolic execution to transform the program’s LLVM code into an integer transition system (ITS). These ITSs are analyzed by our backend tools KoAT (for termination) and LoAT (for non-termination) which we integrated into our novel framework to replace previously used external backend tools. In this way, we benefit from the recent improvements in the backend tools KoAT and LoAT. The transformation steps in AProVE and the tools in the backend produce sub-proofs which are then combined automatically in order to generate a complete termination proof. If non-termination is proved, then a witness for a non-terminating path in the original C program is returned.