Let x0 of type ι be given.
Let x1 of type ι be given.
Let x2 of type ι be given.
Apply RealsStruct_lt_trich_impred with
x0,
x1,
x2,
or (or (RealsStruct_lt x0 x1 x2) (x1 = x2)) (RealsStruct_lt x0 x2 x1) leaving 6 subgoals.
The subproof is completed by applying H0.
The subproof is completed by applying H1.
The subproof is completed by applying H2.