Should an if statement be associated with else statement in ocaml?

In ocaml, I want to have many nested if statements and a return value on each of the conditions. The code is becoming complicated like this.

let func arg1 arg2 = 
   if condition1 then arg1+arg2
   else
   (
       //code1
       if condition2 then arg1*arg2
       else
       (
          //code2
          if condition3 then arg1+arg2
          else
          (
             //code3
          )
       )
   )

Instead of such nested statements can I have code like this?

let func arg1 arg2 = 
   if condition1 then arg1+arg2
   //code1
   if condition2 then arg1*arg2
   //code2
   if condition3 then arg1+arg2
   //code3