D e toute<chr_var letter="s" var="long">∫</chr_var> parz au frein le <chr_abbr type="reg" class="dc" expan="pri" cert="no">p-vbar</chr_abbr><chr_var letter="s" var="long">∫</chr_var>tr<chr_abbr type="reg" class="dc" expan="en" cert="no">e-hbar</chr_abbr>t. 