Let x0 of type ι be given.
Apply unknownprop_afbf697e4489c80654ae2bc4c6605f6f1d2a8b7dcfe3f07863a96592ab5c88f5 with
x0.
The subproof is completed by applying H0.
Apply unknownprop_9d54935732f044f1d7b246839daf8ba348c0537db194a1ea4a9ea98310c4d87f with
4ae4a.. (e4431.. x0),
λ x1 . or (prim1 x1 x0) (x1 = e4431.. x0).
Apply unknownprop_1f03c3e4cc230143731a84d6351b78522f6051d5113f644774435abf9cb5a984 with
e4431.. x0.
The subproof is completed by applying L1.