no">9.1 </bdi>Benefits of composite types over groups</a></li><li class="tocline"><a class="tocxref" href="#type-checking"><bdi class="secno">9.2 </bdi>Type checking</a></li><li class="tocline"><a class="tocxref" href="#tool-support"><bdi class="secno">9.3 </bdi>Tool support</a><ol class="toc"><li class="tocline"><a class="tocxref" href="#fallbacks"><bdi class="secno">9.3.1 </bdi>Fallbacks</a></li><li class="tocline"><a class="tocxref" href="#appending-custom-type-definitions"><bdi class="secno">9.3.2 </bdi