commons: address TODOs, added to refactoring suggestions in #300

Author: madmike200590

alpha-commons/src/main/java/at/ac/tuwien/kr/alpha/commons/terms/ArithmeticTermImpl.java

@@ -147,7 +147,7 @@ public Integer evaluateExpression() {
 		return arithmeticOperator.eval(leftInt, rightInt);
 	}
 
-	// FIXME it doesn't seem like this class is really needed, could be handled by an if in ArithmeticTermImpl#getInstance
+	// Note: It doesn't seem like this class is really needed, could be handled by an if in ArithmeticTermImpl#getInstance.
 	public static class MinusTerm extends ArithmeticTermImpl {
 
 		private MinusTerm(Term term) {

alpha-commons/src/main/java/at/ac/tuwien/kr/alpha/commons/terms/Terms.java

@@ -97,15 +97,13 @@ public static Substitution renameVariables(Set<VariableTerm> terms, String varNa
 		return renamingSubstitution;
 	}
 
-	// TODO break this into separate class to avoid cyclic dependency Terms <-> ArithmeticTermImpl
 	public static Integer evaluateGroundTerm(Term term) {
 		if (!term.isGround()) {
 			throw new RuntimeException("Cannot evaluate arithmetic term since it is not ground: " + term);
 		}
 		return evaluateGroundTermHelper(term);
 	}
 
-	// TODO break this into separate class to avoid cyclic dependency Terms <-> ArithmeticTermImpl	
 	static Integer evaluateGroundTermHelper(Term term) {
 		if (term instanceof ConstantTerm
 				&& ((ConstantTerm<?>) term).getObject() instanceof Integer) {