l3lab/ntp-mathlib huggingface dataset:
instance commRing : CommRing ℝ := by
  refine' { natCast := fun n => ⟨n⟩
            intCast := fun z => ⟨z⟩
            zero := (0 : ℝ)
            one := (1 : ℝ)
            mul := (· * ·)
            add := (· + ·)
            neg := @Neg.neg ℝ _
            sub := @Sub.sub ℝ _
            npow := @npowRec ℝ ⟨1⟩ ⟨(· * ·)⟩
            nsmul := @nsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩
            zsmul := @zsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩ ⟨@Neg.neg ℝ _⟩,
            .. }
  all_goals
    intros
    first
    | rfl
    | apply ext_cauchy
      simp [cauchy_add, cauchy_zero, cauchy_one, cauchy_neg, cauchy_mul,
        cauchy_natCast, cauchy_intCast]
      

Proof state:
case refine'_6.a
x y a✝ b✝ : ℝ
⊢ a✝.cauchy + b✝.cauchy = b✝.cauchy + a✝.cauchy

Next tactic:
first
        | done
        | apply add_assoc
        | apply add_comm
        | apply left_distrib
        | apply right_distrib
        | apply mul_assoc
        | apply mul_comm
instance commRing : CommRing ℝ := by
  refine' { natCast := fun n => ⟨n⟩
            intCast := fun z => ⟨z⟩
            zero := (0 : ℝ)
            one := (1 : ℝ)
            mul := (· * ·)
            add := (· + ·)
            neg := @Neg.neg ℝ _
            sub := @Sub.sub ℝ _
            npow := @npowRec ℝ ⟨1⟩ ⟨(· * ·)⟩
            nsmul := @nsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩
            zsmul := @zsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩ ⟨@Neg.neg ℝ _⟩,
            .. }
  all_goals
    intros
    first
    | rfl
    | apply ext_cauchy
      simp [cauchy_add, cauchy_zero, cauchy_one, cauchy_neg, cauchy_mul,
        cauchy_natCast, cauchy_intCast]
      first
        | 

Proof state:
case refine'_6.a
x y a✝ b✝ : ℝ
⊢ a✝.cauchy + b✝.cauchy = b✝.cauchy + a✝.cauchy

Next tactic:
done
instance commRing : CommRing ℝ := by
  refine' { natCast := fun n => ⟨n⟩
            intCast := fun z => ⟨z⟩
            zero := (0 : ℝ)
            one := (1 : ℝ)
            mul := (· * ·)
            add := (· + ·)
            neg := @Neg.neg ℝ _
            sub := @Sub.sub ℝ _
            npow := @npowRec ℝ ⟨1⟩ ⟨(· * ·)⟩
            nsmul := @nsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩
            zsmul := @zsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩ ⟨@Neg.neg ℝ _⟩,
            .. }
  all_goals
    intros
    first
    | rfl
    | apply ext_cauchy
      simp [cauchy_add, cauchy_zero, cauchy_one, cauchy_neg, cauchy_mul,
        cauchy_natCast, cauchy_intCast]
      first
        | done
        | 

Proof state:
case refine'_6.a
x y a✝ b✝ : ℝ
⊢ a✝.cauchy + b✝.cauchy = b✝.cauchy + a✝.cauchy

Next tactic:
apply add_assoc
instance commRing : CommRing ℝ := by
  refine' { natCast := fun n => ⟨n⟩
            intCast := fun z => ⟨z⟩
            zero := (0 : ℝ)
            one := (1 : ℝ)
            mul := (· * ·)
            add := (· + ·)
            neg := @Neg.neg ℝ _
            sub := @Sub.sub ℝ _
            npow := @npowRec ℝ ⟨1⟩ ⟨(· * ·)⟩
            nsmul := @nsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩
            zsmul := @zsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩ ⟨@Neg.neg ℝ _⟩,
            .. }
  all_goals
    intros
    first
    | rfl
    | apply ext_cauchy
      simp [cauchy_add, cauchy_zero, cauchy_one, cauchy_neg, cauchy_mul,
        cauchy_natCast, cauchy_intCast]
      first
        | done
        | apply add_assoc
        | 

Proof state:
case refine'_6.a
x y a✝ b✝ : ℝ
⊢ a✝.cauchy + b✝.cauchy = b✝.cauchy + a✝.cauchy

Next tactic:
apply add_comm
instance commRing : CommRing ℝ := by
  refine' { natCast := fun n => ⟨n⟩
            intCast := fun z => ⟨z⟩
            zero := (0 : ℝ)
            one := (1 : ℝ)
            mul := (· * ·)
            add := (· + ·)
            neg := @Neg.neg ℝ _
            sub := @Sub.sub ℝ _
            npow := @npowRec ℝ ⟨1⟩ ⟨(· * ·)⟩
            nsmul := @nsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩
            zsmul := @zsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩ ⟨@Neg.neg ℝ _⟩,
            .. }
  all_goals
    

Proof state:
case refine'_7
x y : ℝ
⊢ ∀ (a b c : ℝ), a * (b + c) = a * b + a * c

Next tactic:
intros
instance commRing : CommRing ℝ := by
  refine' { natCast := fun n => ⟨n⟩
            intCast := fun z => ⟨z⟩
            zero := (0 : ℝ)
            one := (1 : ℝ)
            mul := (· * ·)
            add := (· + ·)
            neg := @Neg.neg ℝ _
            sub := @Sub.sub ℝ _
            npow := @npowRec ℝ ⟨1⟩ ⟨(· * ·)⟩
            nsmul := @nsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩
            zsmul := @zsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩ ⟨@Neg.neg ℝ _⟩,
            .. }
  all_goals
    intros
    

Proof state:
case refine'_7
x y a✝ b✝ c✝ : ℝ
⊢ a✝ * (b✝ + c✝) = a✝ * b✝ + a✝ * c✝

Next tactic:
first
    | rfl
    | apply ext_cauchy
      simp [cauchy_add, cauchy_zero, cauchy_one, cauchy_neg, cauchy_mul,
        cauchy_natCast, cauchy_intCast]
      first
        | done
        | apply add_assoc
        | apply add_comm
        | apply left_distrib
        | apply right_distrib
        | apply mul_assoc
        | apply mul_comm
instance commRing : CommRing ℝ := by
  refine' { natCast := fun n => ⟨n⟩
            intCast := fun z => ⟨z⟩
            zero := (0 : ℝ)
            one := (1 : ℝ)
            mul := (· * ·)
            add := (· + ·)
            neg := @Neg.neg ℝ _
            sub := @Sub.sub ℝ _
            npow := @npowRec ℝ ⟨1⟩ ⟨(· * ·)⟩
            nsmul := @nsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩
            zsmul := @zsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩ ⟨@Neg.neg ℝ _⟩,
            .. }
  all_goals
    intros
    first
    | 

Proof state:
case refine'_7
x y a✝ b✝ c✝ : ℝ
⊢ a✝ * (b✝ + c✝) = a✝ * b✝ + a✝ * c✝

Next tactic:
rfl
instance commRing : CommRing ℝ := by
  refine' { natCast := fun n => ⟨n⟩
            intCast := fun z => ⟨z⟩
            zero := (0 : ℝ)
            one := (1 : ℝ)
            mul := (· * ·)
            add := (· + ·)
            neg := @Neg.neg ℝ _
            sub := @Sub.sub ℝ _
            npow := @npowRec ℝ ⟨1⟩ ⟨(· * ·)⟩
            nsmul := @nsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩
            zsmul := @zsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩ ⟨@Neg.neg ℝ _⟩,
            .. }
  all_goals
    intros
    first
    | rfl
    | 

Proof state:
case refine'_7
x y a✝ b✝ c✝ : ℝ
⊢ a✝ * (b✝ + c✝) = a✝ * b✝ + a✝ * c✝

Next tactic:
apply ext_cauchy
instance commRing : CommRing ℝ := by
  refine' { natCast := fun n => ⟨n⟩
            intCast := fun z => ⟨z⟩
            zero := (0 : ℝ)
            one := (1 : ℝ)
            mul := (· * ·)
            add := (· + ·)
            neg := @Neg.neg ℝ _
            sub := @Sub.sub ℝ _
            npow := @npowRec ℝ ⟨1⟩ ⟨(· * ·)⟩
            nsmul := @nsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩
            zsmul := @zsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩ ⟨@Neg.neg ℝ _⟩,
            .. }
  all_goals
    intros
    first
    | rfl
    | apply ext_cauchy
      

Proof state:
case refine'_7.a
x y a✝ b✝ c✝ : ℝ
⊢ (a✝ * (b✝ + c✝)).cauchy = (a✝ * b✝ + a✝ * c✝).cauchy

Next tactic:
simp [cauchy_add, cauchy_zero, cauchy_one, cauchy_neg, cauchy_mul,
        cauchy_natCast, cauchy_intCast]
instance commRing : CommRing ℝ := by
  refine' { natCast := fun n => ⟨n⟩
            intCast := fun z => ⟨z⟩
            zero := (0 : ℝ)
            one := (1 : ℝ)
            mul := (· * ·)
            add := (· + ·)
            neg := @Neg.neg ℝ _
            sub := @Sub.sub ℝ _
            npow := @npowRec ℝ ⟨1⟩ ⟨(· * ·)⟩
            nsmul := @nsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩
            zsmul := @zsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩ ⟨@Neg.neg ℝ _⟩,
            .. }
  all_goals
    intros
    first
    | rfl
    | apply ext_cauchy
      simp [cauchy_add, cauchy_zero, cauchy_one, cauchy_neg, cauchy_mul,
        cauchy_natCast, cauchy_intCast]
      

Proof state:
case refine'_7.a
x y a✝ b✝ c✝ : ℝ
⊢ a✝.cauchy * (b✝.cauchy + c✝.cauchy) = a✝.cauchy * b✝.cauchy + a✝.cauchy * c✝.cauchy

Next tactic:
first
        | done
        | apply add_assoc
        | apply add_comm
        | apply left_distrib
        | apply right_distrib
        | apply mul_assoc
        | apply mul_comm
instance commRing : CommRing ℝ := by
  refine' { natCast := fun n => ⟨n⟩
            intCast := fun z => ⟨z⟩
            zero := (0 : ℝ)
            one := (1 : ℝ)
            mul := (· * ·)
            add := (· + ·)
            neg := @Neg.neg ℝ _
            sub := @Sub.sub ℝ _
            npow := @npowRec ℝ ⟨1⟩ ⟨(· * ·)⟩
            nsmul := @nsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩
            zsmul := @zsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩ ⟨@Neg.neg ℝ _⟩,
            .. }
  all_goals
    intros
    first
    | rfl
    | apply ext_cauchy
      simp [cauchy_add, cauchy_zero, cauchy_one, cauchy_neg, cauchy_mul,
        cauchy_natCast, cauchy_intCast]
      first
        | 

Proof state:
case refine'_7.a
x y a✝ b✝ c✝ : ℝ
⊢ a✝.cauchy * (b✝.cauchy + c✝.cauchy) = a✝.cauchy * b✝.cauchy + a✝.cauchy * c✝.cauchy

Next tactic:
done
instance commRing : CommRing ℝ := by
  refine' { natCast := fun n => ⟨n⟩
            intCast := fun z => ⟨z⟩
            zero := (0 : ℝ)
            one := (1 : ℝ)
            mul := (· * ·)
            add := (· + ·)
            neg := @Neg.neg ℝ _
            sub := @Sub.sub ℝ _
            npow := @npowRec ℝ ⟨1⟩ ⟨(· * ·)⟩
            nsmul := @nsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩
            zsmul := @zsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩ ⟨@Neg.neg ℝ _⟩,
            .. }
  all_goals
    intros
    first
    | rfl
    | apply ext_cauchy
      simp [cauchy_add, cauchy_zero, cauchy_one, cauchy_neg, cauchy_mul,
        cauchy_natCast, cauchy_intCast]
      first
        | done
        | 

Proof state:
case refine'_7.a
x y a✝ b✝ c✝ : ℝ
⊢ a✝.cauchy * (b✝.cauchy + c✝.cauchy) = a✝.cauchy * b✝.cauchy + a✝.cauchy * c✝.cauchy

Next tactic:
apply add_assoc
instance commRing : CommRing ℝ := by
  refine' { natCast := fun n => ⟨n⟩
            intCast := fun z => ⟨z⟩
            zero := (0 : ℝ)
            one := (1 : ℝ)
            mul := (· * ·)
            add := (· + ·)
            neg := @Neg.neg ℝ _
            sub := @Sub.sub ℝ _
            npow := @npowRec ℝ ⟨1⟩ ⟨(· * ·)⟩
            nsmul := @nsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩
            zsmul := @zsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩ ⟨@Neg.neg ℝ _⟩,
            .. }
  all_goals
    intros
    first
    | rfl
    | apply ext_cauchy
      simp [cauchy_add, cauchy_zero, cauchy_one, cauchy_neg, cauchy_mul,
        cauchy_natCast, cauchy_intCast]
      first
        | done
        | apply add_assoc
        | 

Proof state:
case refine'_7.a
x y a✝ b✝ c✝ : ℝ
⊢ a✝.cauchy * (b✝.cauchy + c✝.cauchy) = a✝.cauchy * b✝.cauchy + a✝.cauchy * c✝.cauchy

Next tactic:
apply add_comm
instance commRing : CommRing ℝ := by
  refine' { natCast := fun n => ⟨n⟩
            intCast := fun z => ⟨z⟩
            zero := (0 : ℝ)
            one := (1 : ℝ)
            mul := (· * ·)
            add := (· + ·)
            neg := @Neg.neg ℝ _
            sub := @Sub.sub ℝ _
            npow := @npowRec ℝ ⟨1⟩ ⟨(· * ·)⟩
            nsmul := @nsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩
            zsmul := @zsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩ ⟨@Neg.neg ℝ _⟩,
            .. }
  all_goals
    intros
    first
    | rfl
    | apply ext_cauchy
      simp [cauchy_add, cauchy_zero, cauchy_one, cauchy_neg, cauchy_mul,
        cauchy_natCast, cauchy_intCast]
      first
        | done
        | apply add_assoc
        | apply add_comm
        | 

Proof state:
case refine'_7.a
x y a✝ b✝ c✝ : ℝ
⊢ a✝.cauchy * (b✝.cauchy + c✝.cauchy) = a✝.cauchy * b✝.cauchy + a✝.cauchy * c✝.cauchy

Next tactic:
apply left_distrib
instance commRing : CommRing ℝ := by
  refine' { natCast := fun n => ⟨n⟩
            intCast := fun z => ⟨z⟩
            zero := (0 : ℝ)
            one := (1 : ℝ)
            mul := (· * ·)
            add := (· + ·)
            neg := @Neg.neg ℝ _
            sub := @Sub.sub ℝ _
            npow := @npowRec ℝ ⟨1⟩ ⟨(· * ·)⟩
            nsmul := @nsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩
            zsmul := @zsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩ ⟨@Neg.neg ℝ _⟩,
            .. }
  all_goals
    

Proof state:
case refine'_8
x y : ℝ
⊢ ∀ (a b c : ℝ), (a + b) * c = a * c + b * c

Next tactic:
intros
instance commRing : CommRing ℝ := by
  refine' { natCast := fun n => ⟨n⟩
            intCast := fun z => ⟨z⟩
            zero := (0 : ℝ)
            one := (1 : ℝ)
            mul := (· * ·)
            add := (· + ·)
            neg := @Neg.neg ℝ _
            sub := @Sub.sub ℝ _
            npow := @npowRec ℝ ⟨1⟩ ⟨(· * ·)⟩
            nsmul := @nsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩
            zsmul := @zsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩ ⟨@Neg.neg ℝ _⟩,
            .. }
  all_goals
    intros
    

Proof state:
case refine'_8
x y a✝ b✝ c✝ : ℝ
⊢ (a✝ + b✝) * c✝ = a✝ * c✝ + b✝ * c✝

Next tactic:
first
    | rfl
    | apply ext_cauchy
      simp [cauchy_add, cauchy_zero, cauchy_one, cauchy_neg, cauchy_mul,
        cauchy_natCast, cauchy_intCast]
      first
        | done
        | apply add_assoc
        | apply add_comm
        | apply left_distrib
        | apply right_distrib
        | apply mul_assoc
        | apply mul_comm
instance commRing : CommRing ℝ := by
  refine' { natCast := fun n => ⟨n⟩
            intCast := fun z => ⟨z⟩
            zero := (0 : ℝ)
            one := (1 : ℝ)
            mul := (· * ·)
            add := (· + ·)
            neg := @Neg.neg ℝ _
            sub := @Sub.sub ℝ _
            npow := @npowRec ℝ ⟨1⟩ ⟨(· * ·)⟩
            nsmul := @nsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩
            zsmul := @zsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩ ⟨@Neg.neg ℝ _⟩,
            .. }
  all_goals
    intros
    first
    | 

Proof state:
case refine'_8
x y a✝ b✝ c✝ : ℝ
⊢ (a✝ + b✝) * c✝ = a✝ * c✝ + b✝ * c✝

Next tactic:
rfl
instance commRing : CommRing ℝ := by
  refine' { natCast := fun n => ⟨n⟩
            intCast := fun z => ⟨z⟩
            zero := (0 : ℝ)
            one := (1 : ℝ)
            mul := (· * ·)
            add := (· + ·)
            neg := @Neg.neg ℝ _
            sub := @Sub.sub ℝ _
            npow := @npowRec ℝ ⟨1⟩ ⟨(· * ·)⟩
            nsmul := @nsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩
            zsmul := @zsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩ ⟨@Neg.neg ℝ _⟩,
            .. }
  all_goals
    intros
    first
    | rfl
    | 

Proof state:
case refine'_8
x y a✝ b✝ c✝ : ℝ
⊢ (a✝ + b✝) * c✝ = a✝ * c✝ + b✝ * c✝

Next tactic:
apply ext_cauchy
instance commRing : CommRing ℝ := by
  refine' { natCast := fun n => ⟨n⟩
            intCast := fun z => ⟨z⟩
            zero := (0 : ℝ)
            one := (1 : ℝ)
            mul := (· * ·)
            add := (· + ·)
            neg := @Neg.neg ℝ _
            sub := @Sub.sub ℝ _
            npow := @npowRec ℝ ⟨1⟩ ⟨(· * ·)⟩
            nsmul := @nsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩
            zsmul := @zsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩ ⟨@Neg.neg ℝ _⟩,
            .. }
  all_goals
    intros
    first
    | rfl
    | apply ext_cauchy
      

Proof state:
case refine'_8.a
x y a✝ b✝ c✝ : ℝ
⊢ ((a✝ + b✝) * c✝).cauchy = (a✝ * c✝ + b✝ * c✝).cauchy

Next tactic:
simp [cauchy_add, cauchy_zero, cauchy_one, cauchy_neg, cauchy_mul,
        cauchy_natCast, cauchy_intCast]
instance commRing : CommRing ℝ := by
  refine' { natCast := fun n => ⟨n⟩
            intCast := fun z => ⟨z⟩
            zero := (0 : ℝ)
            one := (1 : ℝ)
            mul := (· * ·)
            add := (· + ·)
            neg := @Neg.neg ℝ _
            sub := @Sub.sub ℝ _
            npow := @npowRec ℝ ⟨1⟩ ⟨(· * ·)⟩
            nsmul := @nsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩
            zsmul := @zsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩ ⟨@Neg.neg ℝ _⟩,
            .. }
  all_goals
    intros
    first
    | rfl
    | apply ext_cauchy
      simp [cauchy_add, cauchy_zero, cauchy_one, cauchy_neg, cauchy_mul,
        cauchy_natCast, cauchy_intCast]
      

Proof state:
case refine'_8.a
x y a✝ b✝ c✝ : ℝ
⊢ (a✝.cauchy + b✝.cauchy) * c✝.cauchy = a✝.cauchy * c✝.cauchy + b✝.cauchy * c✝.cauchy

Next tactic:
first
        | done
        | apply add_assoc
        | apply add_comm
        | apply left_distrib
        | apply right_distrib
        | apply mul_assoc
        | apply mul_comm
instance commRing : CommRing ℝ := by
  refine' { natCast := fun n => ⟨n⟩
            intCast := fun z => ⟨z⟩
            zero := (0 : ℝ)
            one := (1 : ℝ)
            mul := (· * ·)
            add := (· + ·)
            neg := @Neg.neg ℝ _
            sub := @Sub.sub ℝ _
            npow := @npowRec ℝ ⟨1⟩ ⟨(· * ·)⟩
            nsmul := @nsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩
            zsmul := @zsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩ ⟨@Neg.neg ℝ _⟩,
            .. }
  all_goals
    intros
    first
    | rfl
    | apply ext_cauchy
      simp [cauchy_add, cauchy_zero, cauchy_one, cauchy_neg, cauchy_mul,
        cauchy_natCast, cauchy_intCast]
      first
        | 

Proof state:
case refine'_8.a
x y a✝ b✝ c✝ : ℝ
⊢ (a✝.cauchy + b✝.cauchy) * c✝.cauchy = a✝.cauchy * c✝.cauchy + b✝.cauchy * c✝.cauchy

Next tactic:
done
instance commRing : CommRing ℝ := by
  refine' { natCast := fun n => ⟨n⟩
            intCast := fun z => ⟨z⟩
            zero := (0 : ℝ)
            one := (1 : ℝ)
            mul := (· * ·)
            add := (· + ·)
            neg := @Neg.neg ℝ _
            sub := @Sub.sub ℝ _
            npow := @npowRec ℝ ⟨1⟩ ⟨(· * ·)⟩
            nsmul := @nsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩
            zsmul := @zsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩ ⟨@Neg.neg ℝ _⟩,
            .. }
  all_goals
    intros
    first
    | rfl
    | apply ext_cauchy
      simp [cauchy_add, cauchy_zero, cauchy_one, cauchy_neg, cauchy_mul,
        cauchy_natCast, cauchy_intCast]
      first
        | done
        | 

Proof state:
case refine'_8.a
x y a✝ b✝ c✝ : ℝ
⊢ (a✝.cauchy + b✝.cauchy) * c✝.cauchy = a✝.cauchy * c✝.cauchy + b✝.cauchy * c✝.cauchy

Next tactic:
apply add_assoc
instance commRing : CommRing ℝ := by
  refine' { natCast := fun n => ⟨n⟩
            intCast := fun z => ⟨z⟩
            zero := (0 : ℝ)
            one := (1 : ℝ)
            mul := (· * ·)
            add := (· + ·)
            neg := @Neg.neg ℝ _
            sub := @Sub.sub ℝ _
            npow := @npowRec ℝ ⟨1⟩ ⟨(· * ·)⟩
            nsmul := @nsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩
            zsmul := @zsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩ ⟨@Neg.neg ℝ _⟩,
            .. }
  all_goals
    intros
    first
    | rfl
    | apply ext_cauchy
      simp [cauchy_add, cauchy_zero, cauchy_one, cauchy_neg, cauchy_mul,
        cauchy_natCast, cauchy_intCast]
      first
        | done
        | apply add_assoc
        | 

Proof state:
case refine'_8.a
x y a✝ b✝ c✝ : ℝ
⊢ (a✝.cauchy + b✝.cauchy) * c✝.cauchy = a✝.cauchy * c✝.cauchy + b✝.cauchy * c✝.cauchy

Next tactic:
apply add_comm
instance commRing : CommRing ℝ := by
  refine' { natCast := fun n => ⟨n⟩
            intCast := fun z => ⟨z⟩
            zero := (0 : ℝ)
            one := (1 : ℝ)
            mul := (· * ·)
            add := (· + ·)
            neg := @Neg.neg ℝ _
            sub := @Sub.sub ℝ _
            npow := @npowRec ℝ ⟨1⟩ ⟨(· * ·)⟩
            nsmul := @nsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩
            zsmul := @zsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩ ⟨@Neg.neg ℝ _⟩,
            .. }
  all_goals
    intros
    first
    | rfl
    | apply ext_cauchy
      simp [cauchy_add, cauchy_zero, cauchy_one, cauchy_neg, cauchy_mul,
        cauchy_natCast, cauchy_intCast]
      first
        | done
        | apply add_assoc
        | apply add_comm
        | 

Proof state:
case refine'_8.a
x y a✝ b✝ c✝ : ℝ
⊢ (a✝.cauchy + b✝.cauchy) * c✝.cauchy = a✝.cauchy * c✝.cauchy + b✝.cauchy * c✝.cauchy

Next tactic:
apply left_distrib
instance commRing : CommRing ℝ := by
  refine' { natCast := fun n => ⟨n⟩
            intCast := fun z => ⟨z⟩
            zero := (0 : ℝ)
            one := (1 : ℝ)
            mul := (· * ·)
            add := (· + ·)
            neg := @Neg.neg ℝ _
            sub := @Sub.sub ℝ _
            npow := @npowRec ℝ ⟨1⟩ ⟨(· * ·)⟩
            nsmul := @nsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩
            zsmul := @zsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩ ⟨@Neg.neg ℝ _⟩,
            .. }
  all_goals
    intros
    first
    | rfl
    | apply ext_cauchy
      simp [cauchy_add, cauchy_zero, cauchy_one, cauchy_neg, cauchy_mul,
        cauchy_natCast, cauchy_intCast]
      first
        | done
        | apply add_assoc
        | apply add_comm
        | apply left_distrib
        | 

Proof state:
case refine'_8.a
x y a✝ b✝ c✝ : ℝ
⊢ (a✝.cauchy + b✝.cauchy) * c✝.cauchy = a✝.cauchy * c✝.cauchy + b✝.cauchy * c✝.cauchy

Next tactic:
apply right_distrib
instance commRing : CommRing ℝ := by
  refine' { natCast := fun n => ⟨n⟩
            intCast := fun z => ⟨z⟩
            zero := (0 : ℝ)
            one := (1 : ℝ)
            mul := (· * ·)
            add := (· + ·)
            neg := @Neg.neg ℝ _
            sub := @Sub.sub ℝ _
            npow := @npowRec ℝ ⟨1⟩ ⟨(· * ·)⟩
            nsmul := @nsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩
            zsmul := @zsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩ ⟨@Neg.neg ℝ _⟩,
            .. }
  all_goals
    

Proof state:
case refine'_9
x y : ℝ
⊢ ∀ (a : ℝ), 0 * a = 0

Next tactic:
intros
instance commRing : CommRing ℝ := by
  refine' { natCast := fun n => ⟨n⟩
            intCast := fun z => ⟨z⟩
            zero := (0 : ℝ)
            one := (1 : ℝ)
            mul := (· * ·)
            add := (· + ·)
            neg := @Neg.neg ℝ _
            sub := @Sub.sub ℝ _
            npow := @npowRec ℝ ⟨1⟩ ⟨(· * ·)⟩
            nsmul := @nsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩
            zsmul := @zsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩ ⟨@Neg.neg ℝ _⟩,
            .. }
  all_goals
    intros
    

Proof state:
case refine'_9
x y a✝ : ℝ
⊢ 0 * a✝ = 0

Next tactic:
first
    | rfl
    | apply ext_cauchy
      simp [cauchy_add, cauchy_zero, cauchy_one, cauchy_neg, cauchy_mul,
        cauchy_natCast, cauchy_intCast]
      first
        | done
        | apply add_assoc
        | apply add_comm
        | apply left_distrib
        | apply right_distrib
        | apply mul_assoc
        | apply mul_comm
instance commRing : CommRing ℝ := by
  refine' { natCast := fun n => ⟨n⟩
            intCast := fun z => ⟨z⟩
            zero := (0 : ℝ)
            one := (1 : ℝ)
            mul := (· * ·)
            add := (· + ·)
            neg := @Neg.neg ℝ _
            sub := @Sub.sub ℝ _
            npow := @npowRec ℝ ⟨1⟩ ⟨(· * ·)⟩
            nsmul := @nsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩
            zsmul := @zsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩ ⟨@Neg.neg ℝ _⟩,
            .. }
  all_goals
    intros
    first
    | 

Proof state:
case refine'_9
x y a✝ : ℝ
⊢ 0 * a✝ = 0

Next tactic:
rfl
instance commRing : CommRing ℝ := by
  refine' { natCast := fun n => ⟨n⟩
            intCast := fun z => ⟨z⟩
            zero := (0 : ℝ)
            one := (1 : ℝ)
            mul := (· * ·)
            add := (· + ·)
            neg := @Neg.neg ℝ _
            sub := @Sub.sub ℝ _
            npow := @npowRec ℝ ⟨1⟩ ⟨(· * ·)⟩
            nsmul := @nsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩
            zsmul := @zsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩ ⟨@Neg.neg ℝ _⟩,
            .. }
  all_goals
    intros
    first
    | rfl
    | 

Proof state:
case refine'_9
x y a✝ : ℝ
⊢ 0 * a✝ = 0

Next tactic:
apply ext_cauchy
instance commRing : CommRing ℝ := by
  refine' { natCast := fun n => ⟨n⟩
            intCast := fun z => ⟨z⟩
            zero := (0 : ℝ)
            one := (1 : ℝ)
            mul := (· * ·)
            add := (· + ·)
            neg := @Neg.neg ℝ _
            sub := @Sub.sub ℝ _
            npow := @npowRec ℝ ⟨1⟩ ⟨(· * ·)⟩
            nsmul := @nsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩
            zsmul := @zsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩ ⟨@Neg.neg ℝ _⟩,
            .. }
  all_goals
    intros
    first
    | rfl
    | apply ext_cauchy
      

Proof state:
case refine'_9.a
x y a✝ : ℝ
⊢ (0 * a✝).cauchy = 0.cauchy

Next tactic:
simp [cauchy_add, cauchy_zero, cauchy_one, cauchy_neg, cauchy_mul,
        cauchy_natCast, cauchy_intCast]
instance commRing : CommRing ℝ := by
  refine' { natCast := fun n => ⟨n⟩
            intCast := fun z => ⟨z⟩
            zero := (0 : ℝ)
            one := (1 : ℝ)
            mul := (· * ·)
            add := (· + ·)
            neg := @Neg.neg ℝ _
            sub := @Sub.sub ℝ _
            npow := @npowRec ℝ ⟨1⟩ ⟨(· * ·)⟩
            nsmul := @nsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩
            zsmul := @zsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩ ⟨@Neg.neg ℝ _⟩,
            .. }
  all_goals
    

Proof state:
case refine'_10
x y : ℝ
⊢ ∀ (a : ℝ), a * 0 = 0

Next tactic:
intros