Added ExponentRule8 and fixed results with multiple expressions

.classpath

@@ -11,7 +11,7 @@
 			<attribute name="maven.pomderived" value="true"/>
 		</attributes>
 	</classpathentry>
-	<classpathentry excluding="**|rules/|rules/" kind="src" output="target/classes" path="src/main/resources">
+	<classpathentry excluding="**" kind="src" output="target/classes" path="src/main/resources">
 		<attributes>
 			<attribute name="maven.pomderived" value="true"/>
 		</attributes>

src/main/java/org/warp/picalculator/math/solver/MathSolver.java

@@ -42,11 +42,23 @@ public class MathSolver {
 		int initStepState = 0, endStepState = 0;
 		final AtomicInteger stepState = new AtomicInteger(0);
 		do {
-			lastFunctions[1] = lastFunctions[0];
-			lastFunctions[0] = new ObjectArrayList[stepStates.length];
+			final ObjectArrayList<Function>[] currFncHistory = new ObjectArrayList[stepStates.length];
 			final String stepName = "Step " + stepNumber;
-			for (int i = initStepState; i <= endStepState; i++) {
-				lastFunctions[0][i] = currFnc;
+			if (initStepState > endStepState) {
+				for (int i = initStepState; i < stepStates.length; i++) {
+					currFncHistory[i] = currFnc;
+				}
+				for (int i = 0; i <= initStepState; i++) {
+					currFncHistory[i] = currFnc;
+				}
+			} else {
+				for (int i = initStepState; i <= endStepState; i++) {
+					currFncHistory[i] = currFnc;
+				}
+			}
+			if (currFnc != null) {
+				lastFunctions[1] = lastFunctions[0];
+				lastFunctions[0] = currFncHistory;
 			}
 			lastFnc = currFnc;
 			initStepState = stepState.get();
@@ -200,24 +212,41 @@ public class MathSolver {
 			throws InterruptedException, Error {
 		final ObjectArrayList<Rule> rules = initialFunction.getMathContext().getAcceptableRules(currentAcceptedRules);
 		ObjectArrayList<Function> results = null;
-		Rule appliedRule = null;
+		ObjectArrayList<Rule> appliedRules = new ObjectArrayList<>();
 		out: {
 			for (final Function fnc : fncs) {
+				boolean didSomething = false;
 				for (final Rule rule : rules) {
-					final List<Function> ruleResults = fnc.simplify(rule);
-					if (ruleResults != null && !ruleResults.isEmpty()) {
+					List<Function> ruleResults = fnc.simplify(rule);
+					if ((ruleResults != null && !ruleResults.isEmpty())) {
 						if (results == null) {
 							results = new ObjectArrayList<>();
 						}
 						results.addAll(ruleResults);
-						appliedRule = rule;
+						appliedRules.add(rule);
+						didSomething = true;
 						break;
 					}
 				}
+				if (!didSomething && fncs.size() > 1) {
+					if (results == null) {
+						results = new ObjectArrayList<>();
+					}
+					results.add(fnc);
+				}
 			}
 		}
-		if (StaticVars.debugOn & results != null & appliedRule != null) {
-			Utils.out.println(Utils.OUTPUTLEVEL_DEBUG_VERBOSE, "Math Solver", currentAcceptedRules.toString(), "Applied rule " + appliedRule.getRuleName());
+		if (appliedRules.isEmpty()) results = null;
+		if (StaticVars.debugOn & results != null && !appliedRules.isEmpty()) {
+			StringBuilder rulesStr = new StringBuilder();
+			appliedRules.forEach((r) -> {
+				rulesStr.append(r.getRuleName());
+				rulesStr.append(',');
+			});
+			if (rulesStr.length() > 0) {
+				rulesStr.setLength(rulesStr.length() - 1);
+			}
+			Utils.out.println(Utils.OUTPUTLEVEL_DEBUG_VERBOSE, "Math Solver", currentAcceptedRules.toString(), "Applied rules: " + rulesStr);
 		}
 		return results;
 	}

src/main/resources/default-rules.lst

@@ -18,6 +18,7 @@ ExponentRule1
 ExponentRule2
 ExponentRule3
 ExponentRule4
+ExponentRule8
 ExponentRule9
 ExponentRule15
 ExponentRule16

src/main/resources/rules/ExponentRule8.java

@@ -0,0 +1,70 @@
+/*
+SETTINGS: (please don't move this part)
+ PATH=ExponentRule8
+*/
+
+import org.warp.picalculator.math.Function;
+import org.warp.picalculator.math.FunctionOperator;
+import org.warp.picalculator.math.FunctionDynamic;
+import org.warp.picalculator.math.FunctionSingle;
+import org.warp.picalculator.math.MathContext;
+//Imports
+
+
+import org.warp.picalculator.Error;
+import org.warp.picalculator.math.Function;
+import org.warp.picalculator.math.MathContext;
+import org.warp.picalculator.math.functions.Multiplication;
+import org.warp.picalculator.math.functions.Power;
+import org.warp.picalculator.math.functions.Sum;
+import org.warp.picalculator.math.rules.Rule;
+import org.warp.picalculator.math.rules.RuleType;
+
+import it.unimi.dsi.fastutil.objects.ObjectArrayList;
+
+/**
+ * Exponent rule
+ * (a) ^ (b+c) = a ^ b + a ^ c
+ * 
+ * @author Andrea Cavalli
+ *
+ */
+public class ExponentRule8 implements Rule {
+	// Rule name
+	@Override
+	public String getRuleName() {
+		return "ExponentRule8";
+	}
+
+	// Rule type
+	@Override
+	public RuleType getRuleType() {
+		return RuleType.EXPANSION;
+	}
+
+	/* Rule function
+	   Returns:
+	     - null if it's not executable on the function "f"
+	     - An ObjectArrayList<Function> if it did something
+	*/
+
+	@Override
+	public ObjectArrayList<Function> execute(Function f) {
+		boolean isExecutable = false;
+		if (f instanceof Power) {
+			FunctionOperator fnc = (FunctionOperator) f;
+			if (fnc.getParameter2() instanceof Sum) {
+				Sum sum = (Sum) fnc.getParameter2();
+				MathContext root = f.getMathContext();
+				ObjectArrayList<Function> result = new ObjectArrayList<>();
+				Function a = fnc.getParameter1();
+				Function b = sum.getParameter1();
+				Function c = sum.getParameter2();
+				result.add(new Multiplication(root, new Power(root, a, b), new Power(root, a, c)));
+				return result;
+			}
+		}
+	
+		return null;
+	}
+}

src/main/resources/rules/functions/VariableRule.java

@@ -22,6 +22,7 @@ import org.warp.picalculator.math.functions.Multiplication;
 import org.warp.picalculator.math.functions.Sum;
 import org.warp.picalculator.math.functions.Subtraction;
 import org.warp.picalculator.math.functions.Variable;
+import org.warp.picalculator.math.functions.Variable.V_TYPE;
 import org.warp.picalculator.math.functions.Number;
 
 /**