Let x0 of type ι be given.
Let x1 of type ι be given.
Apply unknownprop_56bd0714abefd533b13603d171a24196c02fb0b6a0af8036287a8ec089f8957d with
λ x2 x3 : ι → ο . x3 (setsum x0 x1).
Apply unknownprop_4ec3261e93b098949bcb767ddc18dfeab1e68ae68e2b47fdb55e525983415999 with
x0,
x1,
λ x2 x3 . setsum x3 (ap (setsum x0 x1) 1) = setsum x0 x1.
Apply unknownprop_2c39d9d1c1e8302d3a58a0d41be91fe2c2b3e716971a3156a5567f49391a957c with
x0,
x1,
λ x2 x3 . setsum x0 x3 = setsum x0 x1.
Let x2 of type ι → ι → ο be given.
The subproof is completed by applying H0.