Productivity.agda:37,3-40,68
Termination checking failed for the following functions:
  expr, term, factor
Problematic calls:
  term
    (at Productivity.agda:38,14-18)
  factor
    (at Productivity.agda:39,14-20)
  Productivity.♯-9
    (at Productivity.agda:40,25-26)
  Productivity.♯-10
    (at Productivity.agda:40,28-29)
  Productivity.♯-12
    (at Productivity.agda:40,45-46)
  expr
    (at Productivity.agda:40,47-51)
