Added @since tags.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/math/trunk@924453 13f79535-47bb-0310-9956-ffa450edef68

src/main/java/org/apache/commons/math/analysis/BinaryFunction.java

@@ -24,6 +24,7 @@ import org.apache.commons.math.FunctionEvaluationException;
 /**
  * Base class for {@link BivariateRealFunction} that can be composed with other functions.
  *
+ * @since 2.1
  * @version $Revision$ $Date$
  */
 public abstract class BinaryFunction implements BivariateRealFunction {

src/main/java/org/apache/commons/math/analysis/BivariateRealFunction.java

@@ -24,6 +24,7 @@ import org.apache.commons.math.FunctionEvaluationException;
 /**
  * An interface representing a bivariate real function.
  *
+ * @since 2.1
  * @version $Revision$ $Date$
  */
 public interface BivariateRealFunction {

src/main/java/org/apache/commons/math/analysis/ComposableFunction.java

@@ -23,6 +23,7 @@ import org.apache.commons.math.FunctionEvaluationException;
 /**
  * Base class for {@link UnivariateRealFunction} that can be composed with other functions.
  *
+ * @since 2.1
  * @version $Revision$ $Date$
  */
 public abstract class ComposableFunction implements UnivariateRealFunction {