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+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.commons.math3;
+
+import org.apache.commons.math3.exception.MathArithmeticException;
+import org.apache.commons.math3.exception.NullArgumentException;
+
+
+/**
+ * Interface representing <a href="http://mathworld.wolfram.com/Field.html">field</a> elements.
+ * @param <T> the type of the field elements
+ * @see Field
+ * @since 2.0
+ */
+public interface FieldElement<T> {
+
+    /** Compute this + a.
+     * @param a element to add
+     * @return a new element representing this + a
+     * @throws NullArgumentException if {@code a} is {@code null}.
+     */
+    T add(T a) throws NullArgumentException;
+
+    /** Compute this - a.
+     * @param a element to subtract
+     * @return a new element representing this - a
+     * @throws NullArgumentException if {@code a} is {@code null}.
+     */
+    T subtract(T a) throws NullArgumentException;
+
+    /**
+     * Returns the additive inverse of {@code this} element.
+     * @return the opposite of {@code this}.
+     */
+    T negate();
+
+    /** Compute n &times; this. Multiplication by an integer number is defined
+     * as the following sum
+     * <center>
+     * n &times; this = &sum;<sub>i=1</sub><sup>n</sup> this.
+     * </center>
+     * @param n Number of times {@code this} must be added to itself.
+     * @return A new element representing n &times; this.
+     */
+    T multiply(int n);
+
+    /** Compute this &times; a.
+     * @param a element to multiply
+     * @return a new element representing this &times; a
+     * @throws NullArgumentException if {@code a} is {@code null}.
+     */
+    T multiply(T a) throws NullArgumentException;
+
+    /** Compute this &divide; a.
+     * @param a element to divide by
+     * @return a new element representing this &divide; a
+     * @throws NullArgumentException if {@code a} is {@code null}.
+     * @throws MathArithmeticException if {@code a} is zero
+     */
+    T divide(T a) throws NullArgumentException, MathArithmeticException;
+
+    /**
+     * Returns the multiplicative inverse of {@code this} element.
+     * @return the inverse of {@code this}.
+     * @throws MathArithmeticException if {@code this} is zero
+     */
+    T reciprocal() throws MathArithmeticException;
+
+    /** Get the {@link Field} to which the instance belongs.
+     * @return {@link Field} to which the instance belongs
+     */
+    Field<T> getField();
+}