Complex sentence: Such equations do not have a general theory; particular cases such as Catalan's conjecture have been tackled, however the majority are solved via ad hoc methods such as Størmer's theorem or even trial and error.
Split into simpler sentences: Such equations do not have a general theory; particular cases such as Catalan's conjecture have been tackled. However, the majority are solved via ad hoc methods such as Størmer's theorem or even trial and error.