from functools import lru_cache

class Symbol:
    _name: str

    def __init__(self, name):
        self._name = name

    @property
    def name(self):
        return self._name

@lru_cache(maxsize=None)
def symbol(name: str) -> Symbol:
    return Symbol(name)

def symbolName(sym: Symbol) -> str:
    # return sym.name[1:]
    return sym.name

def symbolKey(sym: Symbol) -> str:
    return sym.name

def isSymbol(obj) -> bool:
    return isinstance(obj, Symbol)