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.
Let x4 of type ι be given.
Let x5 of type ι be given.
Let x6 of type ι → ο be given.
Assume H1: x6 x0.
Assume H2: x6 x1.
Assume H3: x6 x2.
Assume H4: x6 x3.
Assume H5: x6 x4.
Apply binunionE with
SetAdjoin (SetAdjoin (UPair x0 x1) x2) x3,
Sing x4,
x5,
x6 x5 leaving 3 subgoals.
The subproof is completed by applying H0.
Apply unknownprop_3de4fed6100f7a1644d3bcc671dd5818f525687e19a89aa1d64708dea3801718 with
x0,
x1,
x2,
x3,
x5,
x6 leaving 5 subgoals.
The subproof is completed by applying H6.
The subproof is completed by applying H1.
The subproof is completed by applying H2.
The subproof is completed by applying H3.
The subproof is completed by applying H4.
Apply SingE with
x4,
x5,
λ x7 x8 . x6 x8 leaving 2 subgoals.
The subproof is completed by applying H6.
The subproof is completed by applying H5.