-- main.mcl --
print ["a" + "b",] {}
-- OUTPUT --
Edge: _operator -> composite: []str # 0
Edge: const: str("+") -> _operator # op
Edge: const: str("a") -> _operator # a
Edge: const: str("b") -> _operator # b
Vertex: _operator
Vertex: composite: []str
Vertex: const: str("+")
Vertex: const: str("a")
Vertex: const: str("b")