| (_,_,_,Terms.Step (_,i1,i2,_,_,_)),false,_ ->
if (List.mem i acc) then (false,acc)
else match orphan_murder bag acc i1 with
| (_,_,_,Terms.Step (_,i1,i2,_,_,_)),false,_ ->
if (List.mem i acc) then (false,acc)
else match orphan_murder bag acc i1 with