<apply>
<eq/>
<apply>
<vectorproduct/>
<ci type="vector"> A </ci>
<ci type="vector"> B </ci>
</apply>
<apply>
<times/>
<ci> a </ci>
<ci> b </ci>
<apply>
<sin/>
<ci> θ </ci>
</apply>
<ci type="vector"> N </ci>
</apply>
</apply>