The upward triangle is formed by the sum of number pairs in their natural order.
The downward triangle i~ formed by the differential of each natural pair of numbers.

Reinforcement and Cancellation, as Creation and Destruction, is the binary "on-off"
of the Pulse of the Universe.  The in-breath and out-breath of God.  Alchemical terms
are Coagulation and Dissolution.  All comes into form, returns to Undifferentiated
Consciousness symbolized by the single 0 at base of diamond. 9 is number of completion,
perfection; 9 is number of the Goddess, that universality of cycles whose rhythm pattern
is the shape of Time. This is the symbol for Universal Harmonics.

Link to Universal Harmonics website