<keyword>constructor</keyword>
<keyword>contradiction</keyword>
<keyword>cut</keyword>
<keyword>decompose</keyword>
<keyword>constructor</keyword>
<keyword>contradiction</keyword>
<keyword>cut</keyword>
<keyword>decompose</keyword>
<keyword>reflexivity</keyword>
<keyword>replace</keyword>
<keyword>rewrite</keyword>
<keyword>reflexivity</keyword>
<keyword>replace</keyword>
<keyword>rewrite</keyword>