diff --git a/java_console/models/src/com/fathzer/soft/javaluator/DoubleEvaluator.java b/java_console/models/src/com/fathzer/soft/javaluator/DoubleEvaluator.java
index b6210b2660..c7beed1239 100644
--- a/java_console/models/src/com/fathzer/soft/javaluator/DoubleEvaluator.java
+++ b/java_console/models/src/com/fathzer/soft/javaluator/DoubleEvaluator.java
@@ -120,7 +120,7 @@ public class DoubleEvaluator extends AbstractEvaluator<Double> {
 	/** The negate unary operator in the standard operator precedence.*/
 	public static final Operator NEGATE = new Operator("negate", 1, Operator.Associativity.RIGHT, 3, "negate");
 	/** The negate unary operator in the Excel like operator precedence.*/
-	public static final Operator NEGATE_HIGH = new Operator("-", 1, Operator.Associativity.RIGHT, 5);
+//	public static final Operator NEGATE_HIGH = new Operator("-", 1, Operator.Associativity.RIGHT, 5);
 
 	/** The negate unary operator in the standard operator precedence.*/
 	public static final Operator NOT = new Operator("!", 1, Operator.Associativity.RIGHT, 3);
@@ -245,7 +245,7 @@ public class DoubleEvaluator extends AbstractEvaluator<Double> {
 	 */
 	@Override
 	protected Double evaluate(Operator operator, Iterator<Double> operands, Object evaluationContext) {
-		if (NEGATE.equals(operator) || NEGATE_HIGH.equals(operator)) {
+		if (NEGATE.equals(operator)) {
 			return -operands.next();
 		} else if (NOT.equals(operator) || NOT2.equals(operator)) {
 			return boolean2double(operands.next() != 1.0);
diff --git a/java_console/models/src/com/fathzer/soft/javaluator/Operator.java b/java_console/models/src/com/fathzer/soft/javaluator/Operator.java
index f175246689..65fa4c628b 100644
--- a/java_console/models/src/com/fathzer/soft/javaluator/Operator.java
+++ b/java_console/models/src/com/fathzer/soft/javaluator/Operator.java
@@ -2,6 +2,8 @@ package com.fathzer.soft.javaluator;
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Set;
+import java.util.TreeSet;
 
 /** An <a href="http://en.wikipedia.org/wiki/Operator_(mathematics)">operator</a>.
  * @author Jean-Marc Astesana
@@ -10,8 +12,11 @@ import java.util.List;
 @SuppressWarnings("WeakerAccess")
 public class Operator {
 	private final String rpnSymbol;
+	public static final List<String> _1_OPERATORS = new ArrayList<>();
 	public static final List<String> _2_OPERATORS = new ArrayList<>();
 
+	private static Set<String> symbols = new TreeSet<>(String.CASE_INSENSITIVE_ORDER);
+
 	/** An Operator's <a href="http://en.wikipedia.org/wiki/Operator_associativity">associativity</a>.
 	 */
 	public enum Associativity {
@@ -59,9 +64,17 @@ public class Operator {
 		this.operandCount = operandCount;
 		this.associativity = associativity;
 		this.precedence = precedence;
-		if (operandCount == 2) {
+		if (operandCount == 1) {
+			_1_OPERATORS.add(symbol);
+		} else if (operandCount == 2) {
 			_2_OPERATORS.add(symbol);
+		} else {
+			throw new IllegalStateException("Unexpected operand count: " + symbol);
 		}
+
+		if (symbols.contains(symbol))
+			throw new IllegalStateException("Not unique symbol " + symbol);
+		symbols.add(symbol);
 	}
 
 	/** Gets the operator's symbol.
diff --git a/java_console/models/src/com/rusefi/test/ParserTest.java b/java_console/models/src/com/rusefi/test/ParserTest.java
index e9d5ad32e2..cdae964033 100644
--- a/java_console/models/src/com/rusefi/test/ParserTest.java
+++ b/java_console/models/src/com/rusefi/test/ParserTest.java
@@ -12,12 +12,12 @@ import static org.junit.Assert.assertEquals;
 public class ParserTest {
     @Test
     public void testBooleanConversion() throws ParseException {
+        assertParseB("2 1 >", "2 > 1");
         assertParseB("1 2 + 3 -", "1 + 2 - 3");
         assertParseB("1 2 | 3 |", "1 | 2 | 3");
 
         assertParseB("1 2 + 3 4 5 + / +", "1 + 2 + 3 / (4 +5 )");
 
-        assertParseB("2 1 >", "2 > 1");
         assertParse("rpm 0 >", "rpm > false");
         assertParse("rpm 0 >", "(rpm > false)");
         assertParse("rpm user0 > clt user2 > or", "(rpm > user0) or (clt > user2)");
@@ -49,8 +49,12 @@ public class ParserTest {
         Stack<String> stack = new Stack<>();
 
         for (String token : tokens) {
+            if (Operator._1_OPERATORS.contains(token)) {
+                String a = stack.pop();
 
-            if (takesTwoParams(token)) {
+                stack.push("(" + token + " " + a + ")");
+
+            } else if (takesTwoParameters(token)) {
                 if (stack.size() < 2)
                     throw new IllegalStateException("Not enough " + token);
                 String a = stack.pop();
@@ -61,11 +65,11 @@ public class ParserTest {
             }
         }
         if (stack.size() != 1)
-            throw new IllegalStateException("Unexpected: " + stack);
+            throw new IllegalStateException("Unexpected stack content: " + stack);
         return stack.pop();
     }
 
-    private boolean takesTwoParams(String token) {
+    private boolean takesTwoParameters(String token) {
         return Operator._2_OPERATORS.contains(token);
     }
 
@@ -93,7 +97,7 @@ public class ParserTest {
     private void assertValue(String expectedRpn, String expression, double expectedValue) {
         DoubleEvaluator evaluator = new DoubleEvaluator();
         assertEquals(expectedValue, evaluator.evaluate(expression), 0.001);
-        assertParse(expectedRpn, expression);
+        assertParseB(expectedRpn, expression);
     }
 
     @Test