class_docstr: DimensionSystem represents a coherent set of dimensions.
  
  The constructor takes three parameters:
  
  - base dimensions;
  - derived dimensions: these are defined in terms of the base dimensions
    (for example velocity is defined from the division of length by time);
  - dependency of dimensions: how the derived dimensions depend
    on the base dimensions.
  
  Optionally either the ``derived_dims`` or the ``dimensional_dependencies``
  may be omitted.
docstr: Useless method, kept for compatibility with previous versions.
  
  DO NOT USE.
  
  Check if the system is well defined.
docstr_tok: ["Useless","method",",","kept","for","compatibility","with","previous","versions",".","DO","NOT","USE",".","Check","if","the","system","is","well","defined","."]
code: def is_consistent(self):
      """
      Useless method, kept for compatibility with previous versions.
  
      DO NOT USE.
  
      Check if the system is well defined.
      """
  
      # not enough or too many base dimensions compared to independent
      # dimensions
      # in vector language: the set of vectors do not form a basis
      return self.inv_can_transf_matrix.is_square
  
imports: from __future__ import annotations
  import collections
  from functools import reduce
  from sympy.core.basic import Basic
  from sympy.core.containers import Dict, Tuple
  from sympy.core.singleton import S
  from sympy.core.sorting import default_sort_key
  from sympy.core.symbol import Symbol
  from sympy.core.sympify import sympify
  from sympy.matrices.dense import Matrix
  from sympy.functions.elementary.trigonometric import TrigonometricFunction
  from sympy.core.expr import Expr
  from sympy.core.power import Pow
label_desc: Use image node_id 17 for calling the DimensionSystem obj's underlying member method code with example usage: obj.is_consistent() and returns: self