==SHOP== 
 :Olefin metathesis was first used in petroleum reformation for the synthesis of higher olefins in the Shell higher olefin process (SHOP) under high pressure and high temperatures. 
 The sentence is ambigous. It can mean 
 :(1) olefin metathesis was first used in SHOP, for petroleum reformation, or 
 :(2) the first use of olefin methathesis in petroleum reformulation was SHOP. 
 Also, does SHOP use a metal catalyst?