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 be given.
Let x7 of type ι be given.
Apply binunionI1 with
SetAdjoin (SetAdjoin (SetAdjoin (SetAdjoin (SetAdjoin (UPair x0 x1) x2) x3) x4) x5) x6,
Sing x7,
x6.
The subproof is completed by applying unknownprop_36e2b4b1ba0e5d32476d3ddbeb055229d423c310a3d08dd69f7040171e800526 with x0, x1, x2, x3, x4, x5, x6.