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.
Assume H0: x2 ⊆ x3.
Apply unknownprop_aae4e03000d6619cc34e5a66244db6980d668b70bdfc22610af1046fd13449ea with
x0,
x1,
x2,
x3.
Apply Subq_atleastp with
x2,
x3.
The subproof is completed by applying H0.