code: def well_formed(expr):
      """Check that each Var is only bound once (well formed).
  
      Parameters
      ----------
      expr : tvm.relay.Expr
          The input expression
  
      Returns
      -------
      well_form : bool
          Whether the input expression is well formed
      """
      return _ffi_api.well_formed(expr)
  
imports: from ...ir import IRModule
  from ...relay import transform, build_module
  from ...runtime.ndarray import cpu
  from .None import _ffi_api
  from .feature import Feature
label_desc: Use image node_id 2 for calling a global function with example usage: well_formed(expr) and returns: _ffi_api