Negatable

All Known Implementing Classes:

AndExpression, BooleanExpression, OrExpression, SystemFunctionCall, SystemFunctionCall.Optimized, ValueComparison
```
public interface Negatable
```
This interface is implemented by expressions that returns a boolean value, and returns an expression whose result is the negated boolean value

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`boolean`	`isNegatable(TypeHierarchy th)`	Check whether this specific instance of the expression is negatable
`Expression`	`negate()`	Create an expression that returns the negation of this expression

- Method Detail
  - isNegatable
```
boolean isNegatable(TypeHierarchy th)
```
    Check whether this specific instance of the expression is negatable
    
    Parameters:
    
    th - the type hierarchy cache
    
    Returns:
    
    true if it is
  - negate
```
Expression negate()
```
    Create an expression that returns the negation of this expression
    
    Returns:
    
    the negated expression