code: def markdown_to_doxygen(string):
      """Markdown to Doxygen equations"""
      long_equations = re.sub(
          r"(?<!\\)\$\$(.*?)(?<!\\)\$\$",
          r"\\f[\g<1>\\f]",
          string,
          flags=re.DOTALL,
      )
      inline_equations = re.sub(
          r"(?<!(\\|\$))\$(?!\$)", r"\\f$", long_equations
      )
      return inline_equations
  
label_desc: Use image node_id 1 for calling a global function with example usage: markdown_to_doxygen(string) and returns: inline_equations