C il <chr_abbr type="reg" class="dc" expan="que" cert="no">q-hbar</chr_abbr> tudem<chr_abbr type="reg" class="dc" expan="an" cert="no">a-hbar</chr_abbr>de<chr_var letter="s" var="long">∫</chr_var><chr_abbr type="frq" class="ss" expan="et" cert="yes">et2</chr_abbr> <chr_abbr type="reg" class="dc" expan="qui" cert="no">q-vbar</chr_abbr>er<chr_var letter="s" var="long">∫</chr_var>’ 