class_docstr: A class for arbitrary expressions. 
class_docstr_tok: ["A","class","for","arbitrary","expressions","."]
docstr: Returns True if ``a`` is non-positive. 
docstr_tok: ["Returns","True","if","``","a","``","is","non-positive","."]
code: def is_nonpositive(self, a):
      """Returns True if ``a`` is non-positive."""
      return a.ex.as_coeff_mul()[0].is_nonpositive
  
imports: from sympy.core import sympify, SympifyError
  from sympy.polys.domains.domainelement import DomainElement
  from sympy.polys.domains.characteristiczero import CharacteristicZero
  from sympy.polys.domains.field import Field
  from sympy.polys.domains.simpledomain import SimpleDomain
  from sympy.polys.polyutils import PicklableWithSlots
  from sympy.utilities import public
label_desc: Use image node_id 24 for calling the ExpressionDomain obj's underlying member method code with example usage: obj.is_nonpositive(a) and returns: a