{HEAD ~ The process} 4 wherein {TAIL ~ the foaming agent} is itself in the form of a mousse 
wherein
{ HEAD ~ The process } 4 wherein { TAIL ~ the foaming agent } is itself in the form of a mousse
HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH