sp {four-acceptable-worst*propose*b
   (state <s> ^name four-acceptable-worst)
-->
   (<s> ^operator <op> +)
   (<op> ^name b)
}

sp {four-acceptable-worst*compare*b
   (state <s> ^name four-acceptable-worst
              ^operator <op1> +
                        <op2> +)
   (<op1> ^name b)
   (<op2> ^name a)
-->
   (<s> ^operator <op1> > <op2>)
}