F oi <chr_abbr type="reg" class="dc" expan="que" cert="no">q-hbar</chr_abbr> doi deu <chr_abbr type="frq" class="ss" expan="et" cert="yes">et1</chr_abbr> <chr_var letter="s" var="long">∫</chr_var>a u<chr_abbr type="reg" class="dc" expan="er" cert="no">[apost]</chr_abbr>tu. 