In the excerpts below, two input variables are defined: XMACH and DBFLL. These two variables are inputs to a table lookup function shown in Example 11, “An excerpt giving the example of a function which refers to a previously defined griddedTableDef” below.

<!--                     ==========================                     -->
<!-- ====================   VARIABLE DEFINITIONS   ==================== -->
<!--                     ==========================                     -->


      <!-- ================== -->
      <!--  Input variables   -->
      <!-- ================== -->

  <variableDef name="MachNumber" varID="XMACH" units="" symbol="M">
    <description>
        Mach number (dimensionless) 
    </description>
    <isStdAIAA/>
  </variableDef>

  <variableDef name="dbfll" varID="DBFLL" units="d" sign="+TED" 
                symbol="&#x3B4;bfll">
    <description>
        Lower left body flap deflection, deg, +TED (so deflections are
        always zero or positive).
    </description>
  </variableDef>
	  

	The name attribute is intended for humans to read, perhaps as the signal name in a wiring diagram. Note that "MachNumber" is one of the standard AIAA simulation parameter name.
	The varID attribute is intended for the processing application to read. This must be an XML-valid identifier and must be unique within this model.
	The optional isStdAIAA sub-element indicates this signal is one of the predefined standard variables that most simulation facilities define in their equations of motion code. The name attribute should correspond to the standard AIAA parameter name from [AIAA01] or subsequent standards document
	The optional units attribute describes the units of measure of the variable. See Section 6.5.6, “Units of measure abbreviation” below for a recommended list of units-of-measure abbreviations.
	The optional sign attribute describes the sign convention that applies to this variable. In this case, the lower-left body-flap is positive with trailing-edge-down deflection. See Section 6.5.5, “Common sign convention notation” below for a recommended list of sign abbreviations.
	The optional symbol attribute allows a UNICODE character string that might be used for this variable in a symbols listing.

This DAVE-ML excerpt defines CRBFLLO which is the "independent variable" output from the table lookup function shown in Example 11, “An excerpt giving the example of a function which refers to a previously defined griddedTableDef” below.

      <!-- ================== -->
      <!--  Local variables   -->
      <!-- ================== -->

<!-- PRELIMINARY BUILDUP EQUATIONS -->

<!--  LOWER LEFT BODY FLAP CONTRIBUTIONS -->

<!--    table output signal   -->
  <variableDef name="Cldbfll_0" varID="CRBFLL0" units="">
    <description>
        Output of CRBFLL0 function; rolling moment contribution of
        lower left body flap deflection due to alpha^0 (constant
        term).
    </description>
  </variableDef>
	  

Here the local variable CLBFLL is defined as a calculated quantity, based on several other input or local variables (not shown). Note the description element is used to describe the equation, in FORTRAN-ish human-readable text. The calculation element describes this same equation in MathML-2 content markup syntax; this portion should be used by parsing applications to create either source code, documentation, or run-time calculation structures.

<!--    lower left body flap lift buildup -->
  <variableDef name="CLdbfll" varID="CLBFLL" units="">
    <description>
        Lift contribution of lower left body flap deflection
        CLdbfll = CLdbfll_0 + alpha*(CLdbfll_1 + alpha*(CLdbfll_2 
                            + alpha*CLdbfll_3)) 
    </description>
    <calculation>  
      <math xmlns="http://www.w3.org/1998/Math/MathML">
        <apply>  
        <plus/>
          <ci>CLBFLL0</ci>
          <apply>
            <times/>
            <ci>ALP</ci>
            <apply>
              <plus/>
              <ci>CLBFLL1</ci>
              <apply>
                <times/>
                <ci>ALP</ci>
                <apply>
                  <plus/>
                  <ci>CLBFLL2</ci>
                  <apply> 
                    <times/>
                    <ci>ALP</ci>
                    <ci>CLBFLL3</ci>
                  </apply> <!--            a*c3   -->  
                </apply> <!--        (c2 + a*c3)  -->
              </apply> <!--        a*(c2 + a*c3)  -->
            </apply> <!--    (c1 + a*(c2 + a*c3)) -->
          </apply> <!--    a*(c1 + a*(c2 + a*c3)) -->
        </apply> <!-- c0 + a*(c1 + a*(c2 + a*c3)) -->
      </math>
    </calculation>
  </variableDef>
	  

	This FORTRAN-ish equation, located in the description element, is provided in this example for the benefit of human readers; it should not parsed by the processing application.
	A calculation element always embeds a MathML-2 math element; note the definition of the MathML-2 namespace.
	Each apply tag pair surrounds a math operation (in this example, a plus) operator) and the arguments to that operation (in this case, a variable CLBFLL defined elsewhere is added to the results of the nested apply operation).
	Inner-most apply multiplies variables ALP and CLBFLL3.
	The comments here are useful for humans to understand how the equation is being built up; the processing application ignores all comments.

      <!-- ================== -->
      <!--  Output variables  -->
      <!-- ================== -->

  <variableDef name="CL" varID="CL" units="" sign="+UP" symbol="CL">
    <description>
        Coefficient of lift
        CL = CL0 + CLBFUL + CLBFUR + CLBFLL + CLBFLR + 
                   CLWFL + CLWFR + CLRUD + CLGE + CLLG
    </description>
    <calculation>
      <math>
        <apply> 
          <plus/>
          <ci>CL0</ci>
          <ci>CLBFUL</ci>
          <ci>CLBFUR</ci>
          <ci>CLBFLL</ci>
          <ci>CLBFLR</ci>
          <ci>CLWFL</ci>
          <ci>CLWFR</ci>
          <ci>CLRUD</ci>
          <ci>CLGE</ci>
          <ci>CLLG</ci>
        </apply>
      </math>
    </calculation>
    <isOutput/> 
  </variableDef>
	  

	Here <apply> simply sums the value of these variables, referenced by their varIDs.
	The isOutput element signifies to the processing application that this variable should be made visible to models external to this DAVEfunc.

      <!-- ================== -->
      <!--    ATAN2 example   --> 
      <!-- ================== -->

  <variableDef name="Wind vector roll angle" varID="PHI" units="r">
    <description>
      This encodes the equation PHI = atan2( tan(BETA), sin(ALPHA) ) where atan2
      is the two-argument arc tangent function from the ANSI C standard math
      library; the first argument represents the sine component and the second
      argument is the cosine component.
    </description>
    <calculation>
      <math>
        <apply>
          <csymbol definitionURL="http://daveml.nasa.gov/function_spaces.html#atan2"
                   encoding="text">  
            atan2
          </csymbol>
          <apply>
            <tan/>
            <ci>BETA</ci>   
          </apply>
          <apply>
            <sin/>
            <ci>ALPHA</ci>  
          </apply>
        </apply> 
      </math>
    </calculation>

  </variableDef>
	  

	This excerpt shows how to calculate wind roll angle, phi, from angle of attack and angle of sideslip; it comes from the Apollo aero data book [NAA64].
	The csymbol element is provided by MathML-2 as a means to extend the function set of MathML. Only a limited set of extensions given in this Standard are supported but others may be added to the standard in later versions. Note the specific URL that uniquely identifies this function; it is also the address of the documentation of the interpretation of the atan2 function.
	BETA is the varID of a previously defined variable.
	ALPHA is the varID of a previously defined variable.