Apply nat_complete_ind with
λ x0 . ∀ x1 . nat_p x1 ⟶ mul_nat x0 x0 = mul_nat 2 (mul_nat x1 x1) ⟶ x1 = 0.
Let x0 of type ι be given.
Let x1 of type ι be given.
Apply L6 with
x1 = 0.
Assume H7:
x0 ∈ omega.
Apply H8 with
x1 = 0.
Let x2 of type ι be given.
Apply H9 with
x1 = 0.
Assume H10:
x2 ∈ omega.
Apply dneg with
x1 = 0.
Assume H12: x1 = 0 ⟶ ∀ x3 : ο . x3.
Apply double_nat_cancel with
mul_nat x1 x1,
mul_nat 2 (mul_nat x2 x2) leaving 3 subgoals.
The subproof is completed by applying L4.
Apply mul_nat_p with
2,
mul_nat x2 x2 leaving 2 subgoals.
The subproof is completed by applying nat_2.
Apply mul_nat_p with
x2,
x2 leaving 2 subgoals.
The subproof is completed by applying L13.
The subproof is completed by applying L13.
Claim L16: x1 ∈ x0
Apply ordinal_In_Or_Subq with
x1,
x0,
x1 ∈ x0 leaving 4 subgoals.
Apply nat_p_ordinal with
x1.
The subproof is completed by applying H2.
Apply nat_p_ordinal with
x0.
The subproof is completed by applying H0.
Assume H16: x1 ∈ x0.
The subproof is completed by applying H16.
Assume H16: x0 ⊆ x1.
Apply FalseE with
x1 ∈ x0.
Apply H12.
Apply double_nat_Subq_0 with
mul_nat x1 x1 leaving 2 subgoals.
The subproof is completed by applying L4.
Apply H3 with
λ x3 x4 . x3 ⊆ mul_nat x1 x1.
Apply square_nat_Subq with
x0,
x1 leaving 3 subgoals.
The subproof is completed by applying H0.
The subproof is completed by applying H2.
The subproof is completed by applying H16.
Apply mul_nat_0_inv with
x1,
x1,
x1 = 0 leaving 5 subgoals.
Apply nat_p_omega with
x1.
The subproof is completed by applying H2.
Apply nat_p_omega with
x1.
The subproof is completed by applying H2.
The subproof is completed by applying L17.
Assume H18: x1 = 0.
The subproof is completed by applying H18.
Assume H18: x1 = 0.
The subproof is completed by applying H18.
Claim L17: x2 = 0
Apply H1 with
x1,
x2 leaving 3 subgoals.
The subproof is completed by applying L16.
Apply omega_nat_p with
x2.
The subproof is completed by applying H10.
The subproof is completed by applying L15.
Apply L15 with
λ x3 x4 . x4 = 0.
Apply L17 with
λ x3 x4 . mul_nat 2 (mul_nat x4 x4) = 0.
Apply mul_nat_0R with
0,
λ x3 x4 . mul_nat 2 x4 = 0.
The subproof is completed by applying mul_nat_0R with 2.
Apply H12.
Apply mul_nat_0_inv with
x1,
x1,
x1 = 0 leaving 5 subgoals.
Apply nat_p_omega with
x1.
The subproof is completed by applying H2.
Apply nat_p_omega with
x1.
The subproof is completed by applying H2.
The subproof is completed by applying L18.
Assume H19: x1 = 0.
The subproof is completed by applying H19.
Assume H19: x1 = 0.
The subproof is completed by applying H19.