exceptionalTrace.lean:7:0-7:13: error: maximum recursion depth has been reached
use `set_option maxRecDepth <num>` to increase limit
use `set_option diagnostics true` to get diagnostic information
[Elab.step] expected type: <not-available>, term
    rt + 1
  [Elab.step] expected type: <not-available>, term
      binop% HAdd.hAdd✝ rt 1
    [Elab.step] expected type: <not-available>, term rt