[nukifw]

Nop, for the moment, we try to not "infer user usages"! But if you extract an expression with variable, there will be, obviously, not be repeated:

    let tau =
      let pi = 3.14 in 
      pi + pi

if we extract `pi + pi` it will lead (if you do not give any concrete name) to the following code:

    let fun_name1 pi = 
       pi + pi

    let tau = 
       let pi = 3.14 in 
       fun_name1 pi