| Electronic journals - 1915
...required collineation. * If Postulate VIII were assumed, the first case only would arise. THEOREM 19. // **a projectivity leaves each of three distinct points...invariant it leaves every point of the line invariant.** THEOREM 20. // P is a Pn all points are in P . This theorem follows readily from Postulate VI and Theorem... | |
| OSWALD VEBLEN - 1910
...50, Chap. VI). We have seen that it is equivalent to the proposition: If a projectivity leaves three **points of a line invariant, it leaves every point of the line invariant.** Later, by means of a discussion of order and continuity (terms as yet undefined), we shall prove this... | |
| MEYER GRUPP GABA - 1915
...were assumed, the first case only would arise. 1915] POSTULATES FOR PROJECTIVE GEOMETRY 59 THEOREM 19. **If a projectivity leaves each of three distinct points...invariant it leaves every point of the line invariant.** THEOREM 20. If P is a Pn all points are in P . This theorem follows readily from Postulate VI and Theorem... | |
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