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.
Apply unknownprop_431ff8ff6435faa4c5f86e4f0a6c43deeb7869b72194a714b191972a3eaf6491 with
f4b0e.. x0 x1 x2 x3,
6b27d.. (f4b0e.. x0 x1 x2 x3) = x0 leaving 2 subgoals.
Apply unknownprop_1c4b77a1bdf71ac8c46772d8b01bd6609e54ee74070e16498c4800adfe13c5ca with
x0,
x1,
x2,
x3 leaving 4 subgoals.
The subproof is completed by applying H0.
The subproof is completed by applying H1.
The subproof is completed by applying H2.
The subproof is completed by applying H3.
Apply H5 with
6b27d.. (f4b0e.. x0 x1 x2 x3) = x0.
Let x4 of type ι be given.