<synset id="n13715614" type="n">
<lex_filenum>23<lex_filenum/>
<word lex_id="0">mass number<word/>
<word lex_id="0">nucleon number<word/>
<pointer refs="n13609214">Hypernym<pointer/>
<def>the sum of the number of neutrons and protons in an atomic nucleus<def/>
<synset/>