diff --git a/mihxil-algebra/src/main/java/org/meeuw/math/abstractalgebra/complex/CompleteComplexNumbers.java b/mihxil-algebra/src/main/java/org/meeuw/math/abstractalgebra/complex/CompleteComplexNumbers.java
index cb64b26f..6968617b 100644
--- a/mihxil-algebra/src/main/java/org/meeuw/math/abstractalgebra/complex/CompleteComplexNumbers.java
+++ b/mihxil-algebra/src/main/java/org/meeuw/math/abstractalgebra/complex/CompleteComplexNumbers.java
@@ -52,4 +52,9 @@ public S e() {
         return of(getElementStructure().e());
     }
 
+    @Override
+    public S φ() {
+        return of(getElementStructure().φ());
+    }
+
 }
diff --git a/mihxil-algebra/src/main/java/org/meeuw/math/abstractalgebra/reals/BigDecimalElement.java b/mihxil-algebra/src/main/java/org/meeuw/math/abstractalgebra/reals/BigDecimalElement.java
index 4e5f5066..95d0a759 100644
--- a/mihxil-algebra/src/main/java/org/meeuw/math/abstractalgebra/reals/BigDecimalElement.java
+++ b/mihxil-algebra/src/main/java/org/meeuw/math/abstractalgebra/reals/BigDecimalElement.java
@@ -19,7 +19,6 @@
 import java.util.Optional;
 
 import org.checkerframework.checker.nullness.qual.NonNull;
-import org.meeuw.configuration.ConfigurationService;
 import org.meeuw.math.*;
 import org.meeuw.math.abstractalgebra.*;
 import org.meeuw.math.abstractalgebra.complex.BigComplexNumber;
@@ -29,6 +28,8 @@
 import org.meeuw.math.operators.BasicAlgebraicIntOperator;
 import org.meeuw.math.uncertainnumbers.*;
 
+import static org.meeuw.configuration.ConfigurationService.getConfigurationAspect;
+
 /**
  * A real number (backend by a big decimal), element of {@link BigDecimalElement}.
  * @author Michiel Meeuwissen
@@ -55,7 +56,10 @@ public class BigDecimalElement implements
      * e as a {@link BigDecimalElement}
      * @see Utils#e
      */
-    public static final BigDecimalElement e = new BigDecimalElement(new BigDecimal(Utils.e), new BigDecimal("1e-" +  (Utils.e.length() - 1)));
+    public static final BigDecimalElement e = new BigDecimalElement(
+        new BigDecimal(Utils.e), new BigDecimal("1e-" +  (Utils.e.length() - 1)));
+
+
 
     private final BigDecimal value;
     private final BigDecimal uncertainty;
@@ -111,7 +115,10 @@ public int compareTo(@NonNull BigDecimalElement compare) {
 
     @Override
     public BigDecimalElement sqr() {
-        return new BigDecimalElement(value.multiply(value), uncertainty.multiply(uncertainty));
+        return new BigDecimalElement(
+            value.multiply(value),
+            uncertainty.multiply(uncertainty)
+        );
     }
 
     @Override
@@ -335,7 +342,7 @@ public <F extends AlgebraicElement<F>> Optional<F> castDirectly(Class<F> clazz)
 
     @Override
     public boolean eq(BigDecimalElement that) {
-        return eq(that, Math.round( ConfigurationService.getConfigurationAspect(ConfidenceIntervalConfiguration.class).getSds() + 0.5f));
+        return eq(that, Math.round( getConfigurationAspect(ConfidenceIntervalConfiguration.class).getSds() + 0.5f));
     }
 
     @Override
@@ -346,7 +353,7 @@ public boolean strictlyEquals(Object o) {
     }
     @Override
     public boolean equals(Object o) {
-        if (ConfigurationService.getConfigurationAspect(CompareConfiguration.class).isEqualsIsStrict()) {
+        if (getConfigurationAspect(CompareConfiguration.class).isEqualsIsStrict()) {
             return strictlyEquals(o);
         } else {
             return eq((BigDecimalElement) o);
diff --git a/mihxil-algebra/src/main/java/org/meeuw/math/abstractalgebra/reals/BigDecimalField.java b/mihxil-algebra/src/main/java/org/meeuw/math/abstractalgebra/reals/BigDecimalField.java
index d191e4db..9794231d 100644
--- a/mihxil-algebra/src/main/java/org/meeuw/math/abstractalgebra/reals/BigDecimalField.java
+++ b/mihxil-algebra/src/main/java/org/meeuw/math/abstractalgebra/reals/BigDecimalField.java
@@ -20,7 +20,6 @@
 import java.util.*;
 
 import org.meeuw.math.Example;
-import org.meeuw.math.Utils;
 import org.meeuw.math.abstractalgebra.*;
 import org.meeuw.math.abstractalgebra.complex.BigComplexNumbers;
 import org.meeuw.math.numbers.BigDecimalOperations;
@@ -83,11 +82,16 @@ public BigDecimalElement atan2(BigDecimalElement y, BigDecimalElement x) {
 
     @Override
     public BigDecimalElement pi() {
-        return BigDecimalElement.of(Utils.PI);
+        return BigDecimalElement.PI;
     }
 
     @Override
     public BigDecimalElement e() {
-        return BigDecimalElement.of(Utils.e);
+        return BigDecimalElement.e;
+    }
+
+    @Override
+    public BigDecimalElement φ() {
+        return (BigDecimalElement.ONE.plus(BigDecimalElement.of(5).sqrt())).dividedBy(2);
     }
 }
diff --git a/mihxil-algebra/src/main/java/org/meeuw/math/abstractalgebra/reals/RealField.java b/mihxil-algebra/src/main/java/org/meeuw/math/abstractalgebra/reals/RealField.java
index 5417b188..cd1b7b7f 100644
--- a/mihxil-algebra/src/main/java/org/meeuw/math/abstractalgebra/reals/RealField.java
+++ b/mihxil-algebra/src/main/java/org/meeuw/math/abstractalgebra/reals/RealField.java
@@ -106,4 +106,8 @@ public RealNumber pi() {
     public RealNumber e() {
         return RealNumber.of(Math.E);
     }
+    @Override
+    public RealNumber φ() {
+        return RealNumber.of((1 + Math.sqrt(5)) / 2);
+    }
 }
diff --git a/mihxil-algebra/src/test/java/org/meeuw/test/math/abstractalgebra/DocumentationTest.java b/mihxil-algebra/src/test/java/org/meeuw/test/math/abstractalgebra/DocumentationTest.java
index 2e6379e9..e0233b7b 100644
--- a/mihxil-algebra/src/test/java/org/meeuw/test/math/abstractalgebra/DocumentationTest.java
+++ b/mihxil-algebra/src/test/java/org/meeuw/test/math/abstractalgebra/DocumentationTest.java
@@ -278,12 +278,21 @@ protected <C extends AlgebraicStructure<?>>  List<OperatorCell> getOperators(Cla
                     rest.append(o.stringify("", ""));
                 }
             }
+
             for (AlgebraicComparisonOperator o : target.getSupportedComparisonOperators()) {
                 if (!rest.isEmpty()) {
                     rest.append(' ');
                 }
                 rest.append(o.stringify("", ""));
             }
+
+            for (AlgebraicIntOperator o : target.getSupportedIntOperators()) {
+                if (!rest.isEmpty()) {
+                    rest.append(' ');
+                }
+                rest.append(o.stringify("x", "n"));
+            }
+
             if (!rest.isEmpty()) {
                 ops.add(new OperatorCell(rest).withTitle("other binary operators"));
             }
@@ -308,6 +317,7 @@ protected <C extends AlgebraicStructure<?>>  List<OperatorCell> getOperators(Cla
             }
         }
 
+
         {
             List<String> special = new ArrayList<>();
             appendSpecials(special, clazz);
diff --git a/mihxil-math/src/main/java/org/meeuw/math/abstractalgebra/CompleteField.java b/mihxil-math/src/main/java/org/meeuw/math/abstractalgebra/CompleteField.java
index 9e97ce02..bc91e2eb 100644
--- a/mihxil-math/src/main/java/org/meeuw/math/abstractalgebra/CompleteField.java
+++ b/mihxil-math/src/main/java/org/meeuw/math/abstractalgebra/CompleteField.java
@@ -44,6 +44,14 @@ public interface CompleteField<E extends CompleteFieldElement<E>> extends Field<
 
     E e();
 
+    default E π() {
+        return pi();
+    }
+
+    /**
+     * Golden ratio 1/1 + srt(5)
+     */
+    E φ();
 
     @Override
     default NavigableSet<AlgebraicBinaryOperator> getSupportedOperators() {
diff --git a/mihxil-math/src/main/java/org/meeuw/math/uncertainnumbers/field/UncertainRealField.java b/mihxil-math/src/main/java/org/meeuw/math/uncertainnumbers/field/UncertainRealField.java
index c2984d58..cef4c958 100644
--- a/mihxil-math/src/main/java/org/meeuw/math/uncertainnumbers/field/UncertainRealField.java
+++ b/mihxil-math/src/main/java/org/meeuw/math/uncertainnumbers/field/UncertainRealField.java
@@ -78,4 +78,10 @@ public UncertainReal e() {
         return UncertainDoubleElement.of(Math.E, DoubleUtils.uncertaintyForDouble(Math.E));
     }
 
+    @Override
+    public UncertainReal φ() {
+        double phi = (1d + Math.sqrt(5)) / 2;
+        return UncertainDoubleElement.of(phi, DoubleUtils.uncertaintyForDouble(phi));
+    }
+
 }
diff --git a/mihxil-theories/src/main/java/org/meeuw/theories/abstractalgebra/CompleteFieldTheory.java b/mihxil-theories/src/main/java/org/meeuw/theories/abstractalgebra/CompleteFieldTheory.java
index 6d643764..f4d82ad3 100644
--- a/mihxil-theories/src/main/java/org/meeuw/theories/abstractalgebra/CompleteFieldTheory.java
+++ b/mihxil-theories/src/main/java/org/meeuw/theories/abstractalgebra/CompleteFieldTheory.java
@@ -15,17 +15,21 @@
  */
 package org.meeuw.theories.abstractalgebra;
 
+import java.math.MathContext;
 import java.util.Optional;
 
 import net.jqwik.api.ForAll;
 import net.jqwik.api.Property;
 
+import org.meeuw.configuration.ConfigurationService;
 import org.meeuw.math.NonAlgebraic;
 import org.meeuw.math.abstractalgebra.*;
 import org.meeuw.math.exceptions.IllegalLogarithmException;
 import org.meeuw.math.exceptions.OverflowException;
+import org.meeuw.math.numbers.MathContextConfiguration;
 
 import static org.meeuw.assertj.Assertions.assertThat;
+import static org.meeuw.configuration.ConfigurationService.setConfiguration;
 import static org.meeuw.math.operators.BasicAlgebraicBinaryOperator.POWER;
 import static org.meeuw.math.operators.BasicAlgebraicUnaryOperator.*;
 
@@ -84,4 +88,18 @@ default void cosPi(@ForAll(STRUCTURE) AlgebraicStructure<?> struct) {
         assertThat(casted.pi().cos()).isEqTo(casted.one().negation());
     }
 
+    @Property
+    default void goldenRatio(@ForAll(STRUCTURE) AlgebraicStructure<?> struct) {
+         CompleteField<E> casted = (CompleteField<E>) struct;
+         try {
+             setConfiguration(builder ->
+                 builder.configure(MathContextConfiguration.class,
+                     (mathContextConfiguration) -> mathContextConfiguration.withContext(new MathContext(4))));
+             assertThat(casted.φ().sqr()).isEqTo(casted.φ().plus(casted.one()));
+         } finally {
+             ConfigurationService.resetToDefaults();
+
+         }
+    }
+
 }