Symbol type

1, quantity symbol

For example, pi (π, 3. 14 159265358979), natural rate (e, 2.7 1828), Fibonacci golden section (φ, 0.6 18033), imaginary number (.

2. Operation symbols

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

3. Relationship symbols

For example, "=" is an equal sign, "≈" is an approximate sign, "≦" is an unequal sign and ">" is a greater than sign. "

4. Natural symbols

Such as plus sign, minus sign, plus sign (and the corresponding minus sign? ) )

Step 5 omit symbols

Such as triangle (△), right triangle (Rt△), sine (see trigonometric function), hyperbolic sine function (sinh), function of x (f(x)), limit (lim) and angle (∞).