code: def ambiguities(signatures):
      """All signature pairs such that A is ambiguous with B"""
      signatures = list(map(tuple, signatures))
      return {
          (a, b)
          for a in signatures
          for b in signatures
          if hash(a) < hash(b)
          and ambiguous(a, b)
          and not any(
              supercedes(c, a) and supercedes(c, b) for c in signatures
          )
      }
  
file_path: sympy/sympy/multipledispatch/conflict.py
imports: from .utils import _toposort, groupby
label_desc: Use image node_id 4 for calling a global function with example usage: ambiguities(signatures) and returns: unknown