Remove unnecessary tests

alib2data/src/grammar/ContextFree/CFG.cpp

@@ -33,9 +33,6 @@ GrammarBase* CFG::plunder() && {
 bool CFG::removeTerminalSymbol(const alphabet::Symbol& symbol) {
 	for(const std::pair<alphabet::Symbol, std::set<std::vector<alphabet::Symbol>>>& rule : rules) {
-		if(rule.first == symbol)
-			throw GrammarException("Symbol \"" + (std::string) symbol.getSymbol() + "\" is used in rule.");
-
 		for(const std::vector<alphabet::Symbol>& rhs : rule.second)
 			if(std::find(rhs.begin(), rhs.end(), symbol) != rhs.end())
 				throw GrammarException("Symbol \"" + (std::string) symbol.getSymbol() + "\" is used in rule.");

alib2data/src/grammar/ContextFree/EpsilonFreeCFG.cpp

@@ -33,9 +33,6 @@ GrammarBase* EpsilonFreeCFG::plunder() && {
 bool EpsilonFreeCFG::removeTerminalSymbol(const alphabet::Symbol& symbol) {
 	for(const std::pair<alphabet::Symbol, std::set<std::vector<alphabet::Symbol>>>& rule : rules) {
-		if(rule.first == symbol)
-			throw GrammarException("Symbol \"" + (std::string) symbol.getSymbol() + "\" is used in rule.");
-
 		for(const std::vector<alphabet::Symbol>& rhs : rule.second)
 			if(std::find(rhs.begin(), rhs.end(), symbol) != rhs.end())
 				throw GrammarException("Symbol \"" + (std::string) symbol.getSymbol() + "\" is used in rule.");