inline compare's double dispatch helper method

alib2data/src/alphabet/BarSymbol.cpp

alib2data/src/alphabet/BarSymbol.h

alib2data/src/alphabet/BlankSymbol.cpp

alib2data/src/alphabet/BlankSymbol.h

alib2data/src/alphabet/BottomOfTheStackSymbol.cpp

alib2data/src/alphabet/BottomOfTheStackSymbol.h

alib2data/src/alphabet/EndSymbol.cpp

alib2data/src/alphabet/EndSymbol.h

alib2data/src/alphabet/LabeledSymbol.cpp

alib2data/src/alphabet/LabeledSymbol.h

alib2data/src/alphabet/RankedBarSymbol.cpp

alib2data/src/alphabet/RankedBarSymbol.h

alib2data/src/alphabet/RankedSymbol.cpp

alib2data/src/alphabet/RankedSymbol.h

alib2data/src/alphabet/SubtreeWildcardSymbol.cpp

alib2data/src/alphabet/SubtreeWildcardSymbol.h

alib2data/src/automaton/FSM/CompactNFA.cpp

alib2data/src/automaton/FSM/CompactNFA.h

alib2data/src/automaton/FSM/DFA.cpp

alib2data/src/automaton/FSM/DFA.h