OpenMath XML (source)
<OMOBJ xmlns="http://www.openmath.org/OpenMath">
<OMA><OMS cd="relation1" name="eq"/>
<OMA><OMS cd="hypergeon2" name="apple_F2"/>
<OMV name="a"/>
<OMV name="b1"/>
<OMV name="b2"/>
<OMV name="c1"/>
<OMV name="c2"/>
<OMV name="x"/>
<OMV name="y"/>
</OMA>
<OMA><OMS cd="arith1" name="sum"/>
<OMA><OMS cd="set1" name="cartesian_product"/>
<OMS cd="setname1" name="N"/>
<OMS cd="setname1" name="N"/>
</OMA>
<OMBIND>
<OMS cd="fns1" name="lambda"/>
<OMBVAR>
<OMV name="m"/>
</OMBVAR>
<OMA><OMS cd="arith1" name="times"/>
<OMA><OMS cd="arith1" name="divide"/>
<OMA><OMS cd="arith1" name="times"/>
<OMA><OMS cd="arith1" name="times"/>
<OMA><OMS cd="hypergeo0" name="pochhammer"/>
<OMV name="a"/>
<OMA><OMS cd="arith1" name="plus"/>
<OMA><OMS cd="linalg1" name="vector_selector"/>
<OMI> 1 </OMI>
<OMV name="m"/>
</OMA>
<OMA><OMS cd="linalg1" name="vector_selector"/>
<OMI> 2 </OMI>
<OMV name="m"/>
</OMA>
</OMA>
</OMA>
<OMA><OMS cd="hypergeo0" name="pochhammer"/>
<OMV name="b1"/>
<OMA><OMS cd="linalg1" name="vector_selector"/>
<OMI> 1 </OMI>
<OMV name="m"/>
</OMA>
</OMA>
</OMA>
<OMA><OMS cd="hypergeo0" name="pochhammer"/>
<OMV name="b2"/>
<OMA><OMS cd="linalg1" name="vector_selector"/>
<OMI> 2 </OMI>
<OMV name="m"/>
</OMA>
</OMA>
</OMA>
<OMA><OMS cd="arith1" name="times"/>
<OMA><OMS cd="arith1" name="times"/>
<OMA><OMS cd="arith1" name="times"/>
<OMA><OMS cd="hypergeo0" name="pochhammer"/>
<OMV name="c1"/>
<OMA><OMS cd="linalg1" name="vector_selector"/>
<OMI> 1 </OMI>
<OMV name="m"/>
</OMA>
</OMA>
<OMA><OMS cd="hypergeo0" name="pochhammer"/>
<OMV name="c2"/>
<OMA><OMS cd="linalg1" name="vector_selector"/>
<OMI> 2 </OMI>
<OMV name="m"/>
</OMA>
</OMA>
</OMA>
<OMA><OMS cd="hypergeo0" name="pochhammer"/>
<OMI> 1 </OMI>
<OMA><OMS cd="linalg1" name="vector_selector"/>
<OMI> 1 </OMI>
<OMV name="m"/>
</OMA>
</OMA>
</OMA>
<OMA><OMS cd="hypergeo0" name="pochhammer"/>
<OMI> 1 </OMI>
<OMA><OMS cd="linalg1" name="vector_selector"/>
<OMI> 2 </OMI>
<OMV name="m"/>
</OMA>
</OMA>
</OMA>
</OMA>
<OMA><OMS cd="arith1" name="times"/>
<OMA><OMS cd="arith1" name="power"/>
<OMV name="x"/>
<OMA><OMS cd="hypergeon2" name="vector_selector"/>
<OMI> 1 </OMI>
<OMV name="m"/>
</OMA>
</OMA>
<OMA><OMS cd="arith1" name="power"/>
<OMV name="y"/>
<OMA><OMS cd="hypergeon2" name="vector_selector"/>
<OMI> 2 </OMI>
<OMV name="m"/>
</OMA>
</OMA>
</OMA>
</OMA>
</OMBIND>
</OMA>
</OMA>
</OMOBJ>
Strict Content MathML
<math xmlns="http://www.w3.org/1998/Math/MathML">
<apply><csymbol cd="relation1">eq</csymbol>
<apply><csymbol cd="hypergeon2">apple_F2</csymbol>
<ci>a</ci>
<ci>b1</ci>
<ci>b2</ci>
<ci>c1</ci>
<ci>c2</ci>
<ci>x</ci>
<ci>y</ci>
</apply>
<apply><csymbol cd="arith1">sum</csymbol>
<apply><csymbol cd="set1">cartesian_product</csymbol>
<csymbol cd="setname1">N</csymbol>
<csymbol cd="setname1">N</csymbol>
</apply>
<bind><csymbol cd="fns1">lambda</csymbol>
<bvar><ci>m</ci></bvar>
<apply><csymbol cd="arith1">times</csymbol>
<apply><csymbol cd="arith1">divide</csymbol>
<apply><csymbol cd="arith1">times</csymbol>
<apply><csymbol cd="arith1">times</csymbol>
<apply><csymbol cd="hypergeo0">pochhammer</csymbol>
<ci>a</ci>
<apply><csymbol cd="arith1">plus</csymbol>
<apply><csymbol cd="linalg1">vector_selector</csymbol><cn type="integer">1</cn><ci>m</ci></apply>
<apply><csymbol cd="linalg1">vector_selector</csymbol><cn type="integer">2</cn><ci>m</ci></apply>
</apply>
</apply>
<apply><csymbol cd="hypergeo0">pochhammer</csymbol>
<ci>b1</ci>
<apply><csymbol cd="linalg1">vector_selector</csymbol><cn type="integer">1</cn><ci>m</ci></apply>
</apply>
</apply>
<apply><csymbol cd="hypergeo0">pochhammer</csymbol>
<ci>b2</ci>
<apply><csymbol cd="linalg1">vector_selector</csymbol><cn type="integer">2</cn><ci>m</ci></apply>
</apply>
</apply>
<apply><csymbol cd="arith1">times</csymbol>
<apply><csymbol cd="arith1">times</csymbol>
<apply><csymbol cd="arith1">times</csymbol>
<apply><csymbol cd="hypergeo0">pochhammer</csymbol>
<ci>c1</ci>
<apply><csymbol cd="linalg1">vector_selector</csymbol><cn type="integer">1</cn><ci>m</ci></apply>
</apply>
<apply><csymbol cd="hypergeo0">pochhammer</csymbol>
<ci>c2</ci>
<apply><csymbol cd="linalg1">vector_selector</csymbol><cn type="integer">2</cn><ci>m</ci></apply>
</apply>
</apply>
<apply><csymbol cd="hypergeo0">pochhammer</csymbol>
<cn type="integer">1</cn>
<apply><csymbol cd="linalg1">vector_selector</csymbol><cn type="integer">1</cn><ci>m</ci></apply>
</apply>
</apply>
<apply><csymbol cd="hypergeo0">pochhammer</csymbol>
<cn type="integer">1</cn>
<apply><csymbol cd="linalg1">vector_selector</csymbol><cn type="integer">2</cn><ci>m</ci></apply>
</apply>
</apply>
</apply>
<apply><csymbol cd="arith1">times</csymbol>
<apply><csymbol cd="arith1">power</csymbol>
<ci>x</ci>
<apply><csymbol cd="hypergeon2">vector_selector</csymbol><cn type="integer">1</cn><ci>m</ci></apply>
</apply>
<apply><csymbol cd="arith1">power</csymbol>
<ci>y</ci>
<apply><csymbol cd="hypergeon2">vector_selector</csymbol><cn type="integer">2</cn><ci>m</ci></apply>
</apply>
</apply>
</apply>
</bind>
</apply>
</apply>
</math>
Popcorn
hypergeon2.apple_F2($a, $b1, $b2, $c1, $c2, $x, $y) = arith1.sum(set1.cartesian_product(setname1.N, setname1.N), fns1.lambda[$m -> (hypergeo0.pochhammer($a, linalg1.vector_selector(1, $m) + linalg1.vector_selector(2, $m)) * hypergeo0.pochhammer($b1, linalg1.vector_selector(1, $m)) * hypergeo0.pochhammer($b2, linalg1.vector_selector(2, $m))) / (hypergeo0.pochhammer($c1, linalg1.vector_selector(1, $m)) * hypergeo0.pochhammer($c2, linalg1.vector_selector(2, $m)) * hypergeo0.pochhammer(1, linalg1.vector_selector(1, $m)) * hypergeo0.pochhammer(1, linalg1.vector_selector(2, $m))) * $x ^ hypergeon2.vector_selector(1, $m) * $y ^ hypergeon2.vector_selector(2, $m)])
Rendered Presentation MathML
apple_F2
(
a
,
b
1
,
b
2
,
c
1
,
c
2
,
x
,
y
)
=
∑
m
in
N
×
N
pochhammer
(
a
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m
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+
m
2
)
pochhammer
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b
1
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m
1
)
pochhammer
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b
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m
2
)
pochhammer
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c
1
,
m
1
)
pochhammer
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c
2
,
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2
)
pochhammer
(
1
,
m
1
)
pochhammer
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1
,
m
2
)
x
vector_selector
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1
,
m
)
y
vector_selector
(
2
,
m
)