circ_inst2.m:014: Error: inst name `circ1'/1 expands to an inst containing
circ_inst2.m:014:   itself, which means that processing any reference to it
circ_inst2.m:014:   would require an infinite sequence of expansions.
circ_inst2.m:015: Error: inst name `circ2'/1 expands to an inst containing
circ_inst2.m:015:   itself, which means that processing any reference to it
circ_inst2.m:015:   would require an infinite sequence of expansions.
circ_inst2.m:017: Error: inst name `circ4'/1 expands to an inst containing
circ_inst2.m:017:   itself, which means that processing any reference to it
circ_inst2.m:017:   would require an infinite sequence of expansions.
circ_inst2.m:019: Error: inst name `left'/1 expands to an inst containing
circ_inst2.m:019:   itself through `right'/1, which means that processing any
circ_inst2.m:019:   reference to it would require an infinite sequence of
circ_inst2.m:019:   expansions.
circ_inst2.m:020:   The definition of `right'/1 is here.