秩序

与顺序关系相关的askhandler：正、负等。

class sympy.assumptions.handlers.order.AskNegativeHandler

This is called by ask() when key='negative'.

测试表达式是否小于零（严格）。

实例

>>> from sympy import ask, Q, pi
>>> ask(Q.negative(pi+1)) # this calls AskNegativeHandler.Add
False
>>> ask(Q.negative(pi**2)) # this calls AskNegativeHandler.Pow
False

static Add(expr, assumptions)

正+正->正，负+负->负

static Pow(expr, assumptions)

真实的 ** Even -> NonNegative Real ** 奇数->与基非负相同**正->非负

class sympy.assumptions.handlers.order.AskNonZeroHandler

Handler for key 'zero'. Test that an expression is not identically zero.

class sympy.assumptions.handlers.order.AskPositiveHandler

Handler for key 'positive'. Test that an expression is greater (strict) than zero.