∀ {α : Type u_2} {M : Type u_3} [inst : AddMonoid M] {rels : FreeAddMonoid α → FreeAddMonoid α → Prop}
  {φ ψ : PresentedAddMonoid rels →+ M},
  φ = ψ ↔ ∀ (x : α), φ (PresentedAddMonoid.of rels x) = ψ (PresentedAddMonoid.of rels x)