∀ {M : Type u_1} {N : Type u_2} [inst : MulOneClass M] [inst_1 : MulOneClass N] (c : Con M) (f : N →* M)
  (hf : Function.Surjective ⇑f),
  c.comapQuotientEquivOfSurj f hf = (Con.congr ⋯).trans (Con.quotientKerEquivOfSurjective (c.mk'.comp f) ⋯)