Let x0 of type ο be given.
Let x1 of type ο be given.
Let x2 of type ο be given.
Let x3 of type ο be given.
Assume H0: x0.
Assume H1: x1.
Assume H2: x2.
Assume H3: x3.
Apply andI with
and (and x0 x1) x2,
x3 leaving 2 subgoals.
Apply and3I with
x0,
x1,
x2 leaving 3 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.