Here are the negative and lateral (imaginary) number signs. A negative sign is an upper half circle placed before the number. A lateral sign is a lower half circle placed before the number. A full circle indicates a negative lateral number.

Another tidbit: Yinrih divide the natural numbers {0,1,2,3…} into two sets. One is called “natural” as before, and includes the number zero. They also have “tangible numbers” which are the set of all positive integers {1,2,3,4…}

I like math, but math doesn't like me.