²The characters being replaced are f^n for iterated symbols, -> for operator declarations, ˜> for partial operator declarations, /$\setminus$ for conjunction in conditions, => for rules, <=? for matching, =? for unification, <- for strategy assignment, =>1, =>+, =>*, =>!, and =># for search, and –> for assignments , ===[ rule ]===> for paths with rule, –- label –-> for paths with label, –––> for paths without label, and ===> for arcs in search graph in outputs.