!! +exec+ +jump+
$lst_tit ifval$lst_titend$type_exec
  意义同
  $(ref1)cmdlist_if_$(ref2)cmdlist_if_">if</a>,
  只是 $emph =$emphend ($emph==$emphend), 
  $emph!= $emphend 是在 $emph string1$emphend 与 $emph string2$emphend
  的数值间比较, 不是比较这两个串.
