Excerpt from Atti della Reale Accademia dei Lincei, 1891, Vol. 7: Anno 288; Rendiconti, Pubblicati per Cura dei Segretari, 2. Semestre Il poliedro fondamentale del sottogruppo è noto appena fissato quello del gruppo, che essendo in ogni caso più semplice, conviene per primo ricercare. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.