omplex expression, e.g. 1 / (z^2 + t * i)^t - log(z)"
             value="z - t + 0.1*z^2"></input>

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       <a class="dark-translucent input-control" href="#"><img class="thumbnail" src="images/birds.jpg"></a>
       <a class="dark-translucent input-control" href="#"><img class="thumbnail" src="images/damask.jpg"></a>
       <a class="dark-translucent input-control"