BLNAFF ( edge, iedge, nedge, iface, nface, ifail )
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  Find edges and faces affected by blend

Receives:
  KI_tag_edge              *edge           --- edge

Returns:
  KI_tag_list_edge         *iedge          --- list of affected edges
  KI_int_nitems            *nedge          --- number of edges in 'iedge'
  KI_tag_list_face         *iface          --- list of affected faces
  KI_int_nitems            *nface          --- number of faces in 'iface'
  KI_cod_error             *ifail          --- failure code

Specific errors:
  KI_bad_blend_bound        illegal blend boundary
  KI_not_blended            no blend on edge
  KI_general_body           general body

Description:
  Finds lists of edges and faces that are affected by the blending surface on
  the given edge. The faces in 'iface' and edges in 'iedge' are those partially
  or completely overlapped by the blending surface.

  The list in 'iedge' will always contain the original edge 'edge'.

  This function is not supported for edges on general bodies.