code: def parse_einsum_equation(equation: str) -> Tuple[List[str]]:
      """
      Args
          equation : str
  
       parse the equation in the following manner:
       (running example: "nchw,nwhr->nchr")
  
      step 1: split the equation with delimiter "->"
          e.g.: this will give "nchw,nwhr" and "nchr"
  
      step 2: split the LHS equation string with delimiter ","
          e.g.: this will give input1 : "nchw", input2: "nwhr"
  
      step 3: map each character to a unique integer, which is incremented.
              Iterate over input1, input2 and output, in that order.
              e.g.: input 1, i.e., "nchw" will give vector {0,1,2,3}
                    input 2, i.e, "nwhr" will produce {0,3,2,4}
                    output , i.e. "nchr" will produce {0,1,2,4}
  
      return vectors corresponding to the 2 inputs and the output
      """
      input_output_str = equation.split("->")
      assert (
          len(input_output_str) == 2
      ), "unsupported einsum equation {}".format(equation)
      input_str = input_output_str[0]
      output_str = input_output_str[1]
  
      inputs = input_str.split(",")
  
      in_outs = inputs + [output_str]
      map_char_to_int = {}
  
      def _update_vec(str, map_char_to_int, index):
          vec = []
          for i, s in enumerate(str):
              if s not in map_char_to_int:
                  map_char_to_int[s] = index
                  index += 1
              vec.append(map_char_to_int[s])
          return index, vec
  
      index = 0
      in_outs_vec = []
      for inout_str in in_outs:
          index, vec = _update_vec(inout_str, map_char_to_int, index)
          in_outs_vec.append(vec)
  
      return tuple(in_outs_vec)
  
imports: import math
  import numbers
  from typing import List, Tuple
  import numpy
  from coremltools.converters.mil.mil import Builder
  from coremltools.converters.mil.mil import Var, get_new_symbol, types
  from coremltools.converters.mil.mil.ops.defs.iOS15.elementwise_unary import cast
  from coremltools.converters.mil.mil.types import builtin_to_string, promote_dtypes
  from coremltools.converters.mil.mil.types.symbolic import is_symbolic
label_desc: Use image node_id 7 for calling a global function with example usage: parse_einsum_equation(equation) and returns: tuple, index,  vec