∀ {ι : Type u_1} {M : Type u_3} {N : Type u_4} [inst : Semifield M] [inst_1 : CharZero M] [inst_2 : Semifield N]
  [inst_3 : CharZero N] [inst_4 : Algebra M N] (s : Finset ι) (f : ι → M),
  ↑(s.expect fun i => f i) = s.expect fun i => ↑(f i)