ParamResult and BigRational: Allow +Infinity as well as Infinity in result spec.

This makes it consistent with result testing for non-exact engines.

prism/src/param/BigRational.java

@@ -184,7 +184,7 @@ public final class BigRational extends Number implements Comparable<BigRational>
 	 */
 	public BigRational(String string)
 	{
-		if (string.equals("Infinity") || string.equals("Inf")) {
+		if (string.equals("Infinity") || string.equals("+Infinity") || string.equals("Inf") || string.equals("+Inf")) {
 			this.num = new BigInteger("1");
 			this.den = new BigInteger("0");
 			return;

prism/src/param/ParamResult.java

@@ -132,7 +132,7 @@ public class ParamResult
 	{
 		Expression exprExpected = null;
 		try {
-			if (strExpected.equals("Infinity") || strExpected.equals("Inf")) {
+			if (strExpected.equals("Infinity") || strExpected.equals("+Infinity") || strExpected.equals("Inf") || strExpected.equals("+Inf")) {
 				exprExpected = new ExpressionLiteral(TypeDouble.getInstance(), BigRational.INF);
 			} else if (strExpected.equals("-Infinity") || strExpected.equals("-Inf")) {
 				exprExpected = new ExpressionLiteral(TypeDouble.getInstance(), BigRational.MINF);