TY - JOUR TI - P 2. JO - Canadian mathematical bulletin PY - 1959 SP - 44 EP - 44 VL - 2 IS - 1 UR - http://geodesic.mathdoc.fr/articles/10.1017/S0008439500024917/ DO - 10.1017/S0008439500024917 ID - 10_1017_S0008439500024917 ER -