# is_in_list()

Predicate that checks if an item is in a list.

## Synopsis

is_in_list(list-expression, expression)


## Description

This expression evaluates to true if the value of the list expression parameter contains an item with a value matching the second argument.

## Parameters

list-expression

The list being checked.

expression

The value to search the list for.

## Returns

True ($$1$$) if the value of the list-expression has an item whose value is expression. False ($$0$$) otherwise.

## Examples

If there is a list of agents, Agent_List, then the following conditional applies only to agents whose id is in the list:

if (is_in_list(Agent_List, id)) then ...