I am trying to convert a XSL-FO file with MathML to PDF using Apache FOP 2.1 but I get a few warnings and errors.

**How can I get MathML to be printed to PDF using FOP?**

**My `Test.fo` file:**

```
<?xml version="1.0" encoding="iso-8859-1"?>

<fo:root xmlns:fo="http://www.w3.org/1999/XSL/Format" xmlns="http://www.w3.org/1998/Math/MathML">
    <fo:layout-master-set>
        <fo:simple-page-master master-name="my-page">
            <fo:region-body margin="1in"/>
        </fo:simple-page-master>
    </fo:layout-master-set>
    <fo:page-sequence master-reference="my-page">
         <fo:flow flow-name="xsl-region-body" font="12pt Times">
            <fo:block font-size="1.5em" font-weight="bold" role="html:p">
                <fo:instream-foreign-object>
                    <math display="inline">
                        <mrow>
                            <mi>A</mi>
                            <mo>=</mo>
                            <mi>Ï€</mi>
                            <msup>
                                <mi>r</mi>
                                <mn>2</mn>
                            </msup>
                        </mrow>
                    </math>
                </fo:instream-foreign-object>
            </fo:block>
        </fo:flow>
    </fo:page-sequence>
</fo:root>

```

**The output I get**:

> 
> $ fop test.fo 123.pdf
> 
> 
> Sep 30, 2016 1:45:12 PM org.apache.fop.events.LoggingEventListener
>  processEvent WARNING: Unknown formatting object
>  "{<http://www.w3.org/1998/Math/MathML>}math" encountered (a child of
>  fo:instream-foreign-object}. (See position 13:72)
> 
> 
> Sep 30, 2016 1:45:12 PM org.apache.fop.events.LoggingEventListener
>  processEvent WARNING: Unknown formatting object
>  "{<http://www.w3.org/1998/Math/MathML>}mrow" encountered (a child of
>  math}. (See position 14:13)
> 
> 
> Sep 30, 2016 1:45:12 PM org.apache.fop.events.LoggingEventListener
>  processEvent WARNING: Unknown formatting object
>  "{<http://www.w3.org/1998/Math/MathML>}mi" encountered (a child of
>  mrow}. (See position 15:12)
> 
> 
> Sep 30, 2016 1:45:12 PM org.apache.fop.events.LoggingEventListener
>  processEvent WARNING: Unknown formatting object
>  "{<http://www.w3.org/1998/Math/MathML>}mo" encountered (a child of
>  mrow}. (See position 16:12)
> 
> 
> Sep 30, 2016 1:45:12 PM org.apache.fop.events.LoggingEventListener
>  processEvent WARNING: Unknown formatting object
>  "{<http://www.w3.org/1998/Math/MathML>}mi" encountered (a child of
>  mrow}. (See position 17:12)
> 
> 
> Sep 30, 2016 1:45:12 PM org.apache.fop.events.LoggingEventListener
>  processEvent WARNING: Unknown formatting object
>  "{<http://www.w3.org/1998/Math/MathML>}msup" encountered (a child of
>  mrow}. (See position 18:14)
> 
> 
> Sep 30, 2016 1:45:12 PM org.apache.fop.events.LoggingEventListener
>  processEvent WARNING: Unknown formatting object
>  "{<http://www.w3.org/1998/Math/MathML>}mi" encountered (a child of
>  msup}. (See position 19:13)
> 
> 
> Sep 30, 2016 1:45:12 PM org.apache.fop.events.LoggingEventListener
>  processEvent WARNING: Unknown formatting object
>  "{<http://www.w3.org/1998/Math/MathML>}mn" encountered (a child of
>  msup}. (See position 20:13)
> 
> 
> Sep 30, 2016 1:45:12 PM org.apache.fop.events.LoggingEventListener
>  processEvent SEVERE: The intrinsic dimensions of an
>  instream-foreign-object could not be determined. (See position 12:33)
> 
> 
> Sep 30, 2016 1:45:13 PM org.apache.fop.events.LoggingEventListener
>  processEvent INFO: Rendered page #1.
> 
> 
> 

The output PDF is empty.