mutwftypemismatch.lean:11:0-11:25: error: The termination measures of mutually recursive functions must have the same return type, but the termination measure of Ex1.foo has type
  Nat
while the termination measure of Ex1.bar has type
  Prop
Try using `sizeOf` explicitly
mutwftypemismatch.lean:26:0-26:44: error: The termination measures of mutually recursive functions must have the same return type, but the termination measure of Ex2.foo has type
  Nat
while the termination measure of Ex2.bar has type
  Fin fixed
Try using `sizeOf` explicitly