// open closure "inner" should be closed and escaped at the end of 'outer' context.
fn outer(){
  let x = 0.0
  let inner = | | { 
    x = x+1.0
    x
  } 
  let mid = | | {inner}
  mid
}
let mid = outer();
let inner = mid();
fn dsp(){
 let r = inner()
 r
}