<keyword>symmetry</keyword>
<keyword>simplify</keyword>
<keyword>split</keyword>
+ <keyword>subst</keyword>
<keyword>to</keyword>
<keyword>transitivity</keyword>
<keyword>unfold</keyword>
<keyword>assume</keyword>
<keyword>suppose</keyword>
<keyword>by</keyword>
+ <keyword>is</keyword>
+ <keyword>or</keyword>
+ <keyword>equivalent</keyword>
+ <keyword>equivalently</keyword>
<keyword>we</keyword>
<keyword>prove</keyword>
<keyword>proved</keyword>
<keyword>know</keyword>
<keyword>case</keyword>
<keyword>obtain</keyword>
+ <keyword>done</keyword>
</keyword-list>
<keyword-list _name = "Tacticals" style = "Keyword" case-sensitive="TRUE">
<keyword>first</keyword>
<keyword>focus</keyword>
<keyword>unfocus</keyword>
+ <keyword>progress</keyword>
</keyword-list>