Anima Astrologiae or A Guide for Astrologers by William Lilly 1676

The 81st is to Consider, Whether the Significator be in an Angle or in a Succeedent or Cadent House? For how much any Planet is near to the cusp of any Angle so much is he the stronger: how much farther so much the weaker; and by how much sooner he shall be nearer the cusp of a Cadent House, so much shall he be the weaker; how much the farther, so much the less weak.

82.Whether the Significator receive virtue from any Planet