code: public static double elementMin( DMatrix4x4 a ) {
          double min = a.a11;
          if( a.a12 < min ) min = a.a12;
          if( a.a13 < min ) min = a.a13;
          if( a.a14 < min ) min = a.a14;
          if( a.a21 < min ) min = a.a21;
          if( a.a22 < min ) min = a.a22;
          if( a.a23 < min ) min = a.a23;
          if( a.a24 < min ) min = a.a24;
          if( a.a31 < min ) min = a.a31;
          if( a.a32 < min ) min = a.a32;
          if( a.a33 < min ) min = a.a33;
          if( a.a34 < min ) min = a.a34;
          if( a.a41 < min ) min = a.a41;
          if( a.a42 < min ) min = a.a42;
          if( a.a43 < min ) min = a.a43;
          if( a.a44 < min ) min = a.a44;
  
          return min;
      }
docs: <p>
  Returns the value of the element in the matrix that has the minimum value.<br>
  <br>
  Min{ a<sub>ij</sub> } for all i and j<br>
  </p>
  
  @param a A matrix. Not modified.
  @return The value of element in the matrix with the minimum value.