Let x0 of type ι be given.
Let x1 of type ι be given.
Let x2 of type ι be given.
Let x3 of type ι be given.
Apply L2 with
λ x4 x5 . UPair x0 x3 ∈ x5.
The subproof is completed by applying L3.
Apply UPairE with
UPair x0 x3,
UPair x0 x1,
Sing x0,
x1 = x3 leaving 3 subgoals.
The subproof is completed by applying L4.
Claim L6:
x1 ∈ UPair x0 x3
Apply H5 with
λ x4 x5 . x1 ∈ x5.
The subproof is completed by applying UPairI2 with x0, x1.
Apply UPairE with
x1,
x0,
x3,
x1 = x3 leaving 3 subgoals.
The subproof is completed by applying L6.
Assume H7: x1 = x0.
Claim L8:
x3 ∈ UPair x0 x1
Apply H5 with
λ x4 x5 . x3 ∈ x4.
The subproof is completed by applying UPairI2 with x0, x3.
Apply UPairE with
x3,
x0,
x1,
x1 = x3 leaving 3 subgoals.
The subproof is completed by applying L8.
Assume H9: x3 = x0.
Apply H9 with
λ x4 x5 . x1 = x5.
The subproof is completed by applying H7.
Assume H9: x3 = x1.
Let x4 of type ι → ι → ο be given.
The subproof is completed by applying H9 with λ x5 x6 . x4 x6 x5.
Assume H7: x1 = x3.
The subproof is completed by applying H7.
Let x4 of type ι → ι → ο be given.
The subproof is completed by applying H5 with λ x5 x6 . x4 x6 x5.
Apply Sing_inv with
x0,
UPair x0 x3,
x1 = x3 leaving 2 subgoals.
The subproof is completed by applying L6.
Assume H7:
x0 ∈ UPair x0 x3.
Assume H8:
∀ x4 . x4 ∈ UPair x0 x3 ⟶ x4 = x0.
Claim L9: x3 = x0
Apply H8 with
x3.
The subproof is completed by applying UPairI2 with x0, x3.
Apply L9 with
λ x4 x5 . x1 = x5.
Apply unknownprop_36456668efb81fed7214a2a55c58885a793c080b2e11698015706b30a4b318d6 with
Sing x0,
λ x4 x5 . UPair x0 x1 ∈ x5.
Apply unknownprop_36456668efb81fed7214a2a55c58885a793c080b2e11698015706b30a4b318d6 with
x0,
λ x4 x5 . UPair x0 x1 ∈ UPair x5 (Sing x0).
Apply L10 with
λ x4 x5 . UPair x0 x1 ∈ x4.
The subproof is completed by applying UPairI1 with
UPair x0 x1,
Sing x0.
Let x4 of type ι → ι → ο be given.
Apply SingE with
Sing x0,
UPair x0 x1,
λ x5 x6 . x4 x6 x5.
The subproof is completed by applying L11.
Apply Sing_inv with
x0,
UPair x0 x1,
x1 = x0 leaving 2 subgoals.
The subproof is completed by applying L12.
Assume H13:
x0 ∈ UPair x0 x1.
Assume H14:
∀ x4 . x4 ∈ UPair x0 x1 ⟶ x4 = x0.
Apply H14 with
x1.
The subproof is completed by applying UPairI2 with x0, x1.