d ℓ<sub>1</sub>/ℓ<sub>2</sub>-norms on matrices plus ℓ<sub>1</sub> [<a href="doc_spams010.html#sprechmann">31</a>, <a href="doc_spams010.html#Friedman2010">11</a>];
</li><li class="li-itemize">mixed ℓ<sub>1</sub>/ℓ<sub>∞</sub>-norms on matrices plus ℓ<sub>1</sub>;
</li><li class="li-itemize">group-lasso with ℓ<sub>2</sub> or ℓ<sub>∞</sub>-norms;
</li><li class="li-itemize">group-lasso+ℓ<sub>1</sub>;
</li><li class="li-itemize">multi-task tree-structured sum of ℓ<sub>∞</sub>-norm