docs: def init_algebra(*, default_hs_cls='LocalSpace'):
      """Initialize the algebra system
  
      Args:
          default_hs_cls (str): The name of the :class:`.LocalSpace` subclass
              that should be used when implicitly creating Hilbert spaces, e.g.
              in :class:`.OperatorSymbol`
  
      """
      from qnet.algebra.core.hilbert_space_algebra import LocalSpace
      from qnet.algebra.core.abstract_quantum_algebra import QuantumExpression
      default_hs_cls = getattr(importlib.import_module('qnet'), default_hs_cls)
      if issubclass(default_hs_cls, LocalSpace):
          QuantumExpression._default_hs_cls = default_hs_cls
      else:
          raise TypeError("default_hs_cls must be a subclass of LocalSpace")