[291.] III.
[292.] IV.
[293.] V.
[294.] VI.
[295.] VII.
[296.] VIII.
[297.] IX.
[298.] X.
[299.] XI.
[300.] PROPOSITION I. Probleme.
[301.] PROPOSITION II. Probleme.
[302.] PROPOSITION III. Probleme.
[303.] PROPOSITION IV. Théoreme.
[304.] DÉMONSTRATION.
[305.] PROPOSITION V. Théoreme.
[306.] Demonstration.
[307.] PROPOSITION VI. Theoreme.
[308.] Demonstration.
[309.] PROPOSITION VII. Theoreme.
[310.] Demonstration.
[311.] PROPOSITION VIII. Theoreme.
[312.] Demonstration.
[313.] Définitions.
[314.] I.
[315.] II.
[316.] PROPOSITION IX. Theoreme.
[317.] Demonstration.
[318.] PROPOSITION X. Theoreme.
[319.] Demonstration.
[320.] PROPOSITION XI. Probleme.