Apply not_TwoRamseyProp_atleast_3_4_Power_3.
Apply TwoRamseyProp_atleastp_atleastp with
3,
3,
6,
4,
prim4 3 leaving 3 subgoals.
The subproof is completed by applying H0.
The subproof is completed by applying atleastp_ref with 3.
Apply nat_In_atleastp with
6,
4 leaving 2 subgoals.
The subproof is completed by applying nat_6.
The subproof is completed by applying In_4_6.