code: def kroneckersimp(expr):
      """
      Simplify expressions with KroneckerDelta.
  
      The only simplification currently attempted is to identify multiplicative cancellation:
  
      Examples
      ========
  
      >>> from sympy import KroneckerDelta, kroneckersimp
      >>> from sympy.abc import i
      >>> kroneckersimp(1 + KroneckerDelta(0, i) * KroneckerDelta(1, i))
      1
      """
  
      def args_cancel(args1, args2):
          for i1 in range(2):
              for i2 in range(2):
                  a1 = args1[i1]
                  a2 = args2[i2]
                  a3 = args1[(i1 + 1) % 2]
                  a4 = args2[(i2 + 1) % 2]
                  if Eq(a1, a2) is S.true and Eq(a3, a4) is S.false:
                      return True
          return False
  
      def cancel_kronecker_mul(m):
          args = m.args
          deltas = [a for a in args if isinstance(a, KroneckerDelta)]
          for delta1, delta2 in subsets(deltas, 2):
              args1 = delta1.args
              args2 = delta2.args
              if args_cancel(args1, args2):
                  return S.Zero * m  # In case of oo etc
          return m
  
      if not expr.has(KroneckerDelta):
          return expr
  
      if expr.has(Piecewise):
          expr = expr.rewrite(KroneckerDelta)
  
      newexpr = expr
      expr = None
  
      while newexpr != expr:
          expr = newexpr
          newexpr = expr.replace(
              lambda e: isinstance(e, Mul), cancel_kronecker_mul
          )
  
      return expr
  
imports: from collections import defaultdict
  from sympy.concrete.products import Product
  from sympy.concrete.summations import Sum
  from sympy.core import Basic, S, Add, Mul, Pow, Symbol, sympify, expand_func, Function, Dummy, Expr, factor_terms, expand_power_exp, Eq
  from sympy.core.exprtools import factor_nc
  from sympy.core.parameters import global_parameters
  from sympy.core.function import expand_log, count_ops, _mexpand, nfloat, expand_mul, expand
  from sympy.core.numbers import Float, I, pi, Rational
  from sympy.core.relational import Relational
  from sympy.core.rules import Transform
  from sympy.core.sorting import ordered
  from sympy.core.sympify import _sympify
  from sympy.core.traversal import bottom_up, walk
  from sympy.functions import gamma, exp, sqrt, log, exp_polar, re
  from sympy.functions.combinatorial.factorials import CombinatorialFunction
  from sympy.functions.elementary.complexes import unpolarify, Abs, sign
  from sympy.functions.elementary.exponential import ExpBase
  from sympy.functions.elementary.hyperbolic import HyperbolicFunction
  from sympy.functions.elementary.integers import ceiling
  from sympy.functions.elementary.piecewise import Piecewise, piecewise_fold, piecewise_simplify
  from sympy.functions.elementary.trigonometric import TrigonometricFunction
  from sympy.functions.special.bessel import BesselBase, besselj, besseli, besselk, bessely, jn
  from sympy.functions.special.tensor_functions import KroneckerDelta
  from sympy.integrals.integrals import Integral
  from sympy.matrices.expressions import MatrixExpr, MatAdd, MatMul, MatPow, MatrixSymbol
  from sympy.polys import together, cancel, factor
  from sympy.polys.numberfields.minpoly import _is_sum_surds, _minimal_polynomial_sq
  from sympy.simplify.combsimp import combsimp
  from sympy.simplify.cse_opts import sub_pre, sub_post
  from sympy.simplify.hyperexpand import hyperexpand
  from sympy.simplify.powsimp import powsimp
  from sympy.simplify.radsimp import radsimp, fraction, collect_abs
  from sympy.simplify.sqrtdenest import sqrtdenest
  from sympy.simplify.trigsimp import trigsimp, exptrigsimp
  from sympy.utilities.decorator import deprecated
  from sympy.utilities.iterables import has_variety, sift, subsets, iterable
  from sympy.utilities.misc import as_int
  import mpmath
label_desc: Use image node_id 18 for calling a global function with example usage: kroneckersimp(expr) and returns: expr, False, m, expr, unknown, True