Apply CD_mul_proj0 with
Sing 3,
CSNo,
minus_CSNo,
conj_CSNo,
add_CSNo,
mul_CSNo leaving 5 subgoals.
The subproof is completed by applying quaternion_tag_fresh.
The subproof is completed by applying CSNo_minus_CSNo.
The subproof is completed by applying CSNo_conj_CSNo.
The subproof is completed by applying CSNo_add_CSNo.
The subproof is completed by applying CSNo_mul_CSNo.