Let x0 of type ι be given.
Apply andI with
TransSet (prim3 x0),
∀ x1 . prim1 x1 (prim3 x0) ⟶ TransSet x1 leaving 2 subgoals.
Let x1 of type ι be given.
Apply UnionE_impred with
x0,
x1,
Subq x1 (prim3 x0) leaving 2 subgoals.
The subproof is completed by applying H1.
Let x2 of type ι be given.
Apply H0 with
x2.
The subproof is completed by applying H3.
Apply L4 with
Subq x1 (prim3 x0).
Let x3 of type ι be given.
Apply H5 with
x1,
x3 leaving 2 subgoals.
The subproof is completed by applying H2.
The subproof is completed by applying H7.
Apply UnionI with
x0,
x3,
x2 leaving 2 subgoals.
The subproof is completed by applying L8.
The subproof is completed by applying H3.
Let x1 of type ι be given.
Apply UnionE_impred with
x0,
x1,
TransSet x1 leaving 2 subgoals.
The subproof is completed by applying H1.
Let x2 of type ι be given.
Apply H0 with
x2.
The subproof is completed by applying H3.
Apply ordinal_Hered with
x2,
x1 leaving 2 subgoals.
The subproof is completed by applying L4.
The subproof is completed by applying H2.
Apply L5 with
TransSet x1.
The subproof is completed by applying H6.