Conditional statement in if/then/else form
Name  Type  Opt  Description 

if  symbol  Obligatory. The arguments for the if object start with a conditional statement that uses the same syntax as expr. Refer to the description of the expr object for details. The word follows the conditional statement, which is then followed by a message expression. After the message expression, there is an optional and a second message expression. if evaluates the conditional expression, and if the result is nonzero, evaluates the message expression after the word . Otherwise, it evaluates the second message expression after the word (or does nothing in the case where no and second message expression have been typed in. 

then else  symbol  Message expressions are similar to what you type into a message box, with the following differences:  
$i1 $f1 $s1  symbol  You use  , , or instead of for changeable arguments.
send  symbol  No commas or semicolons are allowed. Messages can be sent to remote receive objects by preceding the message expression with send, followed by the name of the receive object.  
out2  symbol  The keyword if object. If precedes a message expression, the result of the expression is sent out the right outlet instead of the left outlet.  in a message expression creates a second, right outlet for the
bang  In left inlet: Evaluates the conditional statement using the values currently stored. Any of the above messages in the left inlet will evaluate the conditional statement and send out the result. Any inlets which have not yet received a value have the value 0 by default. The number of inlets is determined by how many different changeable arguments are typed in. The maximum number of inlets is 9. 

int  input [int] 
The number in each inlet will be stored in place of the  or argument associated with it. (Example: The number in the second inlet from the left will be stored in place of the and arguments, wherever they appear.)
(inlet1)  input [int] 
Performs the same function as  .
(inlet2)  input [int] 
Performs the same function as  .
(inlet3)  input [int] 
Performs the same function as  .
(inlet4)  input [int] 
Performs the same function as  .
(inlet5)  input [int] 
Performs the same function as  .
(inlet6)  input [int] 
Performs the same function as  .
(inlet7)  input [int] 
Performs the same function as  .
(inlet8)  input [int] 
Performs the same function as  .
(inlet9)  input [int] 
Performs the same function as  .
float  input [float] 
The number in each inlet will be stored in place of the  or argument associated with it. The number will be truncated by a argument.
(inlet1)  input [float] 
Performs the same function as  .
(inlet2)  input [float] 
Performs the same function as  .
(inlet3)  input [float] 
Performs the same function as  .
(inlet4)  input [float] 
Performs the same function as  .
(inlet5)  input [float] 
Performs the same function as  .
(inlet6)  input [float] 
Performs the same function as  .
(inlet7)  input [float] 
Performs the same function as  .
(inlet8)  input [float] 
Performs the same function as  .
(inlet9)  input [float] 
Performs the same function as  .
set  setinput [list] 
In left inlet: The word  , followed by one or more numbers, treats those numbers as if each had come in a different inlet, replacing the stored value with the new value, but the conditional statement is not evaluated and nothing is sent out the outlet. If there are fewer numbers in the message than there are inlets, the stored value in each remaining inlet is left unchanged.
symbol  input [list] 
In left inlet: The word  , followed by a symbol (a word), will be stored in place of the argument.
Name  Description 

!=  Compare two numbers, output 1 if they are not equal 
<  Is less than, comparison of two numbers 
<=  Is less than or equal to, comparison of two numbers 
==  Compare two numbers, output 1 if they are equal 
>  Is greater than, comparison of two numbers 
>=  Is greater than or equal to, comparison of two numbers 
expr  Evaluate a mathematical expression 
select  Select certain inputs, pass the rest on 
Max Basic Tutorial 22: Designing Equations  Max Basic Tutorial 22: Designing Equations 