def METHOD_NAME(self, name: str) -> z3.ExprRef:
    """
    Set up the appropriate variable representation in Z3 based on name and type.
    If an error is encountered or a case is unconsidered, return None.
    """
    typ = self.types[name]
    type_to_z3 = {
        "int": z3.Int,
        "float": z3.Real,
        "bool": z3.Bool,
    }
    if typ in type_to_z3:
        x = type_to_z3[typ](name)
    else:
        raise Z3ParseException(f"Unhandled type {typ}.")
    return x