Function accept_sound_against 

pub fn accept_sound_against(
    inputs: &[&BrepSolid],
    solid: BrepSolid,
    entry: &str,
) -> Result<BrepSolid, KernelRefusal>

accept_sound for a lane whose INPUTS may themselves self-intersect.

A boolean of two bodies that already pass through themselves is entitled to return a result that does: the defect came in with the operand and refusing it here would blame the wrong operation. What must never pass is a crossing the operation ITSELF introduced, so the inputs are scanned only when the output is flagged — the common case pays for one scan, not three.