<chr_abbr type="frq" class="ss" expan="et" cert="yes">et1</chr_abbr> par La goi<chr_var letter="s" var="long">∫</chr_var><chr_var letter="s" var="long">∫</chr_var>e alama<chr_abbr type="reg" class="dc" expan="in" cert="no">i-hbar</chr_abbr> de<chr_var letter="s" var="long">∫</chr_var>tre. 