b) 0.25 to 15% by {HEAD ~ weight}, based on {TAIL ~ total solids} in the composition, of a lead tellurium lithium oxide wherein the lead tellurium lithium oxide comprises 0.1 to 5 wt % Li2O; and 
based on
b ) 0.25 to 15 % by { HEAD ~ weight } , based on { TAIL ~ total solids } in the composition , of a lead tellurium lithium oxide wherein the lead tellurium lithium oxide comprises 0.1 to 5 wt % Li2O ; and
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH