Fixed implicit multiplication symbols, zoom is now 1x, debug steps are printed, fixed missing numeric chars, changed RootSquare base class to FunctionSingle, added two hardcoded multiplication rules, added rootsquarerule, isolated the swing engine from the window, added 2 Fractions rules and 1 exponent rule
Actually, testing for equivalence was only partially implemented (by
considering the commutative property for some FunctionOperators).
Additionally, should it be needed in the future, equivalence testing
would probably be better implemented as a separate, specialized method
anyway.