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_b74dba84fb5dca70c726b1da9e9f4cce12937bd07b4c888ef9b155874d596966 with
x0,
x1,
x2,
x3,
x1 = x3 leaving 2 subgoals.
The subproof is completed by applying H0.
Assume H1: x0 = x2.
Assume H2: x1 = x3.
The subproof is completed by applying H2.