The greater than sign, the less than sign and the equal sign are all written in the left half of Tian Zige, aligned up and down, occupying two squares, the upper left square and the lower left square.

"≒" is a similar symbol, "≒" is a complete equal sign, "∨" is a parallel symbol, "∧" is a vertical symbol, "∧" is a proportional symbol (inverse ratio can be expressed by reciprocal relationship) and "∈" is a symbol.

"?" Contained in the symbol "?" It is an inclusive symbol, "|" means divisible (for example, a|b means "A is divisible by B" and ||b means that R is the greatest power of A divisible by B), and any letter such as X and Y can represent an unknown number 3.

Operation symbol:

Such as plus sign (+), minus sign (-), multiplication sign (× or), division sign (÷ or/), union of two sets (∩), intersection (∩), root sign (∩ ~), logarithm (log, lg, ln,

Relative symbols: for example, "=" is an equal sign, "≈" is an approximate symbol (that is, approximately equal to), "≦" is an unequal sign, and ">" is a greater than sign. "