假设

限制符号对象的可能值

使用假设限制变量或表达式的可能值范围。有关详细信息，请参阅Use Assumptions on Symbolic Variables。要验证条件是否成立，请使用 isAlways。

函数

设置假设

`assume`	Set assumption on symbolic object
`assumeAlso`	Add assumption on symbolic object
`assumptions`	Show assumptions affecting symbolic variable, expression, or function
`in`	Numeric type of symbolic input
`piecewise`	Conditionally defined expression or function

检查条件

`isAlways`	Determine if symbolic conditions are true for all values of variables
`logical`	Determine if symbolic equation, inequality, or condition is true

主题

Use Assumptions on Symbolic Variables
Set, check, and clear assumptions on symbolic variables.
Clear Assumptions and Reset the Symbolic Engine
Remove assumptions and reset the state of the engine.